diff --git a/docs/topics/accessing-cells.md b/docs/topics/accessing-cells.md
index edb71514..a777afc1 100644
--- a/docs/topics/accessing-cells.md
+++ b/docs/topics/accessing-cells.md
@@ -422,8 +422,10 @@ foreach ($worksheet->getRowIterator() as $row) {
     $cellIterator = $row->getCellIterator();
     $cellIterator->setIterateOnlyExistingCells(FALSE); // This loops through all cells,
                                                        //    even if a cell value is not set.
-                                                       // By default, only cells that have a value
-                                                       //    set will be iterated.
+                                                       // For 'TRUE', we loop through cells
+                                                       //    only when their value is set.
+                                                       // If this method is not called,
+                                                       //    the default value is 'false'.
     foreach ($cellIterator as $cell) {
         echo '<td>' .
              $cell->getValue() .
diff --git a/src/PhpSpreadsheet/Style/Style.php b/src/PhpSpreadsheet/Style/Style.php
index c1aa319e..f7c1be23 100644
--- a/src/PhpSpreadsheet/Style/Style.php
+++ b/src/PhpSpreadsheet/Style/Style.php
@@ -42,13 +42,6 @@ class Style extends Supervisor
      */
     protected $numberFormat;
 
-    /**
-     * Conditional styles.
-     *
-     * @var Conditional[]
-     */
-    protected $conditionalStyles;
-
     /**
      * Protection.
      *
@@ -85,7 +78,6 @@ class Style extends Supervisor
         parent::__construct($isSupervisor);
 
         // Initialise values
-        $this->conditionalStyles = [];
         $this->font = new Font($isSupervisor, $isConditional);
         $this->fill = new Fill($isSupervisor, $isConditional);
         $this->borders = new Borders($isSupervisor, $isConditional);
@@ -212,6 +204,8 @@ class Style extends Supervisor
             $rangeEnd = Coordinate::coordinateFromString($rangeB);
 
             // Translate column into index
+            $rangeStart0 = $rangeStart[0];
+            $rangeEnd0 = $rangeEnd[0];
             $rangeStart[0] = Coordinate::columnIndexFromString($rangeStart[0]);
             $rangeEnd[0] = Coordinate::columnIndexFromString($rangeEnd[0]);
 
@@ -361,6 +355,13 @@ class Style extends Supervisor
                     for ($col = $rangeStart[0]; $col <= $rangeEnd[0]; ++$col) {
                         $oldXfIndexes[$this->getActiveSheet()->getColumnDimensionByColumn($col)->getXfIndex()] = true;
                     }
+                    foreach ($this->getActiveSheet()->getColumnIterator($rangeStart0, $rangeEnd0) as $columnIterator) {
+                        $cellIterator = $columnIterator->getCellIterator();
+                        $cellIterator->setIterateOnlyExistingCells(true);
+                        foreach ($cellIterator as $columnCell) {
+                            $columnCell->getStyle()->applyFromArray($pStyles);
+                        }
+                    }
 
                     break;
                 case 'ROW':
@@ -372,6 +373,13 @@ class Style extends Supervisor
                             $oldXfIndexes[$this->getActiveSheet()->getRowDimension($row)->getXfIndex()] = true;
                         }
                     }
+                    foreach ($this->getActiveSheet()->getRowIterator((int) $rangeStart[1], (int) $rangeEnd[1]) as $rowIterator) {
+                        $cellIterator = $rowIterator->getCellIterator();
+                        $cellIterator->setIterateOnlyExistingCells(true);
+                        foreach ($cellIterator as $rowCell) {
+                            $rowCell->getStyle()->applyFromArray($pStyles);
+                        }
+                    }
 
                     break;
                 case 'CELL':
@@ -599,18 +607,12 @@ class Style extends Supervisor
      */
     public function getHashCode()
     {
-        $hashConditionals = '';
-        foreach ($this->conditionalStyles as $conditional) {
-            $hashConditionals .= $conditional->getHashCode();
-        }
-
         return md5(
             $this->fill->getHashCode() .
             $this->font->getHashCode() .
             $this->borders->getHashCode() .
             $this->alignment->getHashCode() .
             $this->numberFormat->getHashCode() .
-            $hashConditionals .
             $this->protection->getHashCode() .
             ($this->quotePrefix ? 't' : 'f') .
             __CLASS__
diff --git a/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php b/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
index 12420d77..714ee7ce 100644
--- a/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
@@ -92,10 +92,11 @@ class ColumnCellIterator extends CellIterator
      */
     public function seek($row = 1)
     {
+        if ($this->onlyExistingCells && !($this->worksheet->cellExistsByColumnAndRow($this->columnIndex, $row))) {
+            throw new PhpSpreadsheetException('In "IterateOnlyExistingCells" mode and Cell does not exist');
+        }
         if (($row < $this->startRow) || ($row > $this->endRow)) {
             throw new PhpSpreadsheetException("Row $row is out of range ({$this->startRow} - {$this->endRow})");
-        } elseif ($this->onlyExistingCells && !($this->worksheet->cellExistsByColumnAndRow($this->columnIndex, $row))) {
-            throw new PhpSpreadsheetException('In "IterateOnlyExistingCells" mode and Cell does not exist');
         }
         $this->currentRow = $row;
 
@@ -113,7 +114,7 @@ class ColumnCellIterator extends CellIterator
     /**
      * Return the current cell in this worksheet column.
      *
-     * @return null|\PhpOffice\PhpSpreadsheet\Cell\Cell
+     * @return \PhpOffice\PhpSpreadsheet\Cell\Cell
      */
     public function current()
     {
@@ -180,18 +181,12 @@ class ColumnCellIterator extends CellIterator
             ) {
                 ++$this->startRow;
             }
-            if ($this->startRow > $this->endRow) {
-                throw new PhpSpreadsheetException('No cells exist within the specified range');
-            }
             while (
                 (!$this->worksheet->cellExistsByColumnAndRow($this->columnIndex, $this->endRow)) &&
                 ($this->endRow >= $this->startRow)
             ) {
                 --$this->endRow;
             }
-            if ($this->endRow < $this->startRow) {
-                throw new PhpSpreadsheetException('No cells exist within the specified range');
-            }
         }
     }
 }
diff --git a/src/PhpSpreadsheet/Worksheet/RowCellIterator.php b/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
index f5576dc7..9b9d54eb 100644
--- a/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
@@ -93,12 +93,14 @@ class RowCellIterator extends CellIterator
      */
     public function seek($column = 'A')
     {
+        $columnx = $column;
         $column = Coordinate::columnIndexFromString($column);
-        if (($column < $this->startColumnIndex) || ($column > $this->endColumnIndex)) {
-            throw new PhpSpreadsheetException("Column $column is out of range ({$this->startColumnIndex} - {$this->endColumnIndex})");
-        } elseif ($this->onlyExistingCells && !($this->worksheet->cellExistsByColumnAndRow($column, $this->rowIndex))) {
+        if ($this->onlyExistingCells && !($this->worksheet->cellExistsByColumnAndRow($column, $this->rowIndex))) {
             throw new PhpSpreadsheetException('In "IterateOnlyExistingCells" mode and Cell does not exist');
         }
+        if (($column < $this->startColumnIndex) || ($column > $this->endColumnIndex)) {
+            throw new PhpSpreadsheetException("Column $columnx is out of range ({$this->startColumnIndex} - {$this->endColumnIndex})");
+        }
         $this->currentColumnIndex = $column;
 
         return $this;
@@ -181,15 +183,9 @@ class RowCellIterator extends CellIterator
             while ((!$this->worksheet->cellExistsByColumnAndRow($this->startColumnIndex, $this->rowIndex)) && ($this->startColumnIndex <= $this->endColumnIndex)) {
                 ++$this->startColumnIndex;
             }
-            if ($this->startColumnIndex > $this->endColumnIndex) {
-                throw new PhpSpreadsheetException('No cells exist within the specified range');
-            }
             while ((!$this->worksheet->cellExistsByColumnAndRow($this->endColumnIndex, $this->rowIndex)) && ($this->endColumnIndex >= $this->startColumnIndex)) {
                 --$this->endColumnIndex;
             }
-            if ($this->endColumnIndex < $this->startColumnIndex) {
-                throw new PhpSpreadsheetException('No cells exist within the specified range');
-            }
         }
     }
 }
diff --git a/tests/PhpSpreadsheetTests/Style/StyleTest.php b/tests/PhpSpreadsheetTests/Style/StyleTest.php
index b695a50b..6f157709 100644
--- a/tests/PhpSpreadsheetTests/Style/StyleTest.php
+++ b/tests/PhpSpreadsheetTests/Style/StyleTest.php
@@ -3,6 +3,7 @@
 namespace PhpOffice\PhpSpreadsheetTests\Style;
 
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
 use PHPUnit\Framework\TestCase;
 
 class StyleTest extends TestCase
@@ -19,4 +20,141 @@ class StyleTest extends TestCase
         $outArray = $cell1style->getStyleArray($styleArray);
         self::assertEquals($styleArray, $outArray['quotePrefix']);
     }
+
+    public function testStyleColumn(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $cellCoordinates = 'A:B';
+        $styleArray = [
+            'font' => [
+                'bold' => true,
+            ],
+        ];
+        $sheet->getStyle($cellCoordinates)->applyFromArray($styleArray);
+        $sheet->setCellValue('A1', 'xxxa1');
+        $sheet->setCellValue('A2', 'xxxa2');
+        $sheet->setCellValue('A3', 'xxxa3');
+        $sheet->setCellValue('B1', 'xxxa1');
+        $sheet->setCellValue('B2', 'xxxa2');
+        $sheet->setCellValue('B3', 'xxxa3');
+        $sheet->setCellValue('C1', 'xxxc1');
+        $sheet->setCellValue('C2', 'xxxc2');
+        $sheet->setCellValue('C3', 'xxxc3');
+        $styleArray = [
+            'font' => [
+                'italic' => true,
+            ],
+        ];
+        $sheet->getStyle($cellCoordinates)->applyFromArray($styleArray);
+        self::assertTrue($sheet->getStyle('A1')->getFont()->getBold());
+        self::assertTrue($sheet->getStyle('B2')->getFont()->getBold());
+        self::assertFalse($sheet->getStyle('C3')->getFont()->getBold());
+        self::assertTrue($sheet->getStyle('A1')->getFont()->getItalic());
+        self::assertTrue($sheet->getStyle('B2')->getFont()->getItalic());
+        self::assertFalse($sheet->getStyle('C3')->getFont()->getItalic());
+    }
+
+    public function testStyleRow(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $cellCoordinates = '2:3';
+        $styleArray = [
+            'font' => [
+                'bold' => true,
+            ],
+        ];
+        $sheet->getStyle($cellCoordinates)->applyFromArray($styleArray);
+        $sheet->setCellValue('A1', 'xxxa1');
+        $sheet->setCellValue('A2', 'xxxa2');
+        $sheet->setCellValue('A3', 'xxxa3');
+        $sheet->setCellValue('B1', 'xxxa1');
+        $sheet->setCellValue('B2', 'xxxa2');
+        $sheet->setCellValue('B3', 'xxxa3');
+        $sheet->setCellValue('C1', 'xxxc1');
+        $sheet->setCellValue('C2', 'xxxc2');
+        $sheet->setCellValue('C3', 'xxxc3');
+        $styleArray = [
+            'font' => [
+                'italic' => true,
+            ],
+        ];
+        $sheet->getStyle($cellCoordinates)->applyFromArray($styleArray);
+        self::assertFalse($sheet->getStyle('A1')->getFont()->getBold());
+        self::assertTrue($sheet->getStyle('B2')->getFont()->getBold());
+        self::assertTrue($sheet->getStyle('C3')->getFont()->getBold());
+        self::assertFalse($sheet->getStyle('A1')->getFont()->getItalic());
+        self::assertTrue($sheet->getStyle('B2')->getFont()->getItalic());
+        self::assertTrue($sheet->getStyle('C3')->getFont()->getItalic());
+    }
+
+    public function testIssue1712A(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $rgb = '4467b8';
+        $sheet->fromArray(['OK', 'KO']);
+        $spreadsheet->getActiveSheet()
+            ->getStyle('A1')
+            ->getFill()
+            ->setFillType(Fill::FILL_SOLID)
+            ->getStartColor()
+            ->setRGB($rgb);
+        $spreadsheet->getActiveSheet()
+            ->getStyle('B')
+            ->getFill()
+            ->setFillType(Fill::FILL_SOLID)
+            ->getStartColor()
+            ->setRGB($rgb);
+        self::assertEquals($rgb, $sheet->getCell('A1')->getStyle()->getFill()->getStartColor()->getRGB());
+        self::assertEquals($rgb, $sheet->getCell('B1')->getStyle()->getFill()->getStartColor()->getRGB());
+    }
+
+    public function testIssue1712B(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $rgb = '4467b8';
+        $spreadsheet->getActiveSheet()
+            ->getStyle('A1')
+            ->getFill()
+            ->setFillType(Fill::FILL_SOLID)
+            ->getStartColor()
+            ->setRGB($rgb);
+        $spreadsheet->getActiveSheet()
+            ->getStyle('B')
+            ->getFill()
+            ->setFillType(Fill::FILL_SOLID)
+            ->getStartColor()
+            ->setRGB($rgb);
+        $sheet->fromArray(['OK', 'KO']);
+        self::assertEquals($rgb, $sheet->getCell('A1')->getStyle()->getFill()->getStartColor()->getRGB());
+        self::assertEquals($rgb, $sheet->getCell('B1')->getStyle()->getFill()->getStartColor()->getRGB());
+    }
+
+    public function testStyleLoopUpwards(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $cellCoordinates = 'C5:A3';
+        $styleArray = [
+            'font' => [
+                'bold' => true,
+            ],
+        ];
+        $sheet->getStyle($cellCoordinates)->applyFromArray($styleArray);
+        $sheet->setCellValue('A1', 'xxxa1');
+        $sheet->setCellValue('A2', 'xxxa2');
+        $sheet->setCellValue('A3', 'xxxa3');
+        $sheet->setCellValue('B1', 'xxxa1');
+        $sheet->setCellValue('B2', 'xxxa2');
+        $sheet->setCellValue('B3', 'xxxa3');
+        $sheet->setCellValue('C1', 'xxxc1');
+        $sheet->setCellValue('C2', 'xxxc2');
+        $sheet->setCellValue('C3', 'xxxc3');
+        self::assertFalse($sheet->getStyle('A1')->getFont()->getBold());
+        self::assertFalse($sheet->getStyle('B2')->getFont()->getBold());
+        self::assertTrue($sheet->getStyle('C3')->getFont()->getBold());
+    }
 }
diff --git a/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIterator2Test.php b/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIterator2Test.php
new file mode 100644
index 00000000..c542d89e
--- /dev/null
+++ b/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIterator2Test.php
@@ -0,0 +1,75 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
+
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\ColumnCellIterator;
+use PHPUnit\Framework\TestCase;
+
+class ColumnCellIterator2Test extends TestCase
+{
+    /**
+     * @dataProvider providerExistingCell
+     */
+    public function testEndRange(?bool $existing, string $expectedResultFirst, string $expectedResultLast): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $sheet->getCell('B2')->setValue('cellb2');
+        $sheet->getCell('B6')->setValue('cellb6');
+
+        $iterator = new ColumnCellIterator($sheet, 'B', 1, 8);
+        if (isset($existing)) {
+            $iterator->setIterateOnlyExistingCells($existing);
+        }
+        $lastCoordinate = '';
+        $firstCoordinate = '';
+        foreach ($iterator as $cell) {
+            $lastCoordinate = $cell->getCoordinate();
+            if (!$firstCoordinate) {
+                $firstCoordinate = $lastCoordinate;
+            }
+        }
+        self::assertEquals($expectedResultFirst, $firstCoordinate);
+        self::assertEquals($expectedResultLast, $lastCoordinate);
+    }
+
+    public function providerExistingCell(): array
+    {
+        return [
+            [null, 'B1', 'B8'],
+            [false, 'B1', 'B8'],
+            [true, 'B2', 'B6'],
+        ];
+    }
+
+    /**
+     * @dataProvider providerEmptyColumn
+     */
+    public function testEmptyColumn(?bool $existing, int $expectedResult): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $sheet->getCell('B2')->setValue('cellb2');
+        $sheet->getCell('B6')->setValue('cellb6');
+
+        $iterator = new ColumnCellIterator($sheet, 'C');
+        if (isset($existing)) {
+            $iterator->setIterateOnlyExistingCells($existing);
+        }
+        $numCells = 0;
+        foreach ($iterator as $cell) {
+            ++$numCells;
+        }
+        self::assertEquals($expectedResult, $numCells);
+    }
+
+    public function providerEmptyColumn(): array
+    {
+        return [
+            [null, 6],
+            [false, 6],
+            [true, 0],
+        ];
+    }
+}
diff --git a/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php b/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php
index 2083f347..1fa25330 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php
@@ -71,11 +71,21 @@ class ColumnCellIteratorTest extends TestCase
     public function testSeekOutOfRange(): void
     {
         $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
-
+        $this->expectExceptionMessage('Row 1 is out of range');
         $iterator = new ColumnCellIterator($this->mockWorksheet, 'A', 2, 4);
         $iterator->seek(1);
     }
 
+    public function testSeekNotExisting(): void
+    {
+        $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
+        $this->expectExceptionMessage('Cell does not exist');
+
+        $iterator = new ColumnCellIterator($this->mockWorksheet, 'A', 2, 4);
+        $iterator->setIterateOnlyExistingCells(true);
+        $iterator->seek(2);
+    }
+
     public function testPrevOutOfRange(): void
     {
         $iterator = new ColumnCellIterator($this->mockWorksheet, 'A', 2, 4);
diff --git a/tests/PhpSpreadsheetTests/Worksheet/RowCellIterator2Test.php b/tests/PhpSpreadsheetTests/Worksheet/RowCellIterator2Test.php
new file mode 100644
index 00000000..20d10da9
--- /dev/null
+++ b/tests/PhpSpreadsheetTests/Worksheet/RowCellIterator2Test.php
@@ -0,0 +1,75 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
+
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\RowCellIterator;
+use PHPUnit\Framework\TestCase;
+
+class RowCellIterator2Test extends TestCase
+{
+    /**
+     * @dataProvider providerExistingCell
+     */
+    public function testEndRangeTrue(?bool $existing, string $expectedResultFirst, string $expectedResultLast): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $sheet->getCell('C2')->setValue('cellb2');
+        $sheet->getCell('F2')->setValue('cellf2');
+
+        $iterator = new RowCellIterator($sheet, 2, 'B', 'H');
+        if (isset($existing)) {
+            $iterator->setIterateOnlyExistingCells($existing);
+        }
+        $lastCoordinate = '';
+        $firstCoordinate = '';
+        foreach ($iterator as $cell) {
+            $lastCoordinate = $cell->getCoordinate();
+            if (!$firstCoordinate) {
+                $firstCoordinate = $lastCoordinate;
+            }
+        }
+        self::assertEquals($expectedResultFirst, $firstCoordinate);
+        self::assertEquals($expectedResultLast, $lastCoordinate);
+    }
+
+    public function providerExistingCell(): array
+    {
+        return [
+            [null, 'B2', 'H2'],
+            [false, 'B2', 'H2'],
+            [true, 'C2', 'F2'],
+        ];
+    }
+
+    /**
+     * @dataProvider providerEmptyRow
+     */
+    public function testEmptyRow(?bool $existing, int $expectedResult): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $sheet->getCell('B2')->setValue('cellb2');
+        $sheet->getCell('F2')->setValue('cellf2');
+
+        $iterator = new RowCellIterator($sheet, '3');
+        if (isset($existing)) {
+            $iterator->setIterateOnlyExistingCells($existing);
+        }
+        $numCells = 0;
+        foreach ($iterator as $cell) {
+            ++$numCells;
+        }
+        self::assertEquals($expectedResult, $numCells);
+    }
+
+    public function providerEmptyRow(): array
+    {
+        return [
+            [null, 6],
+            [false, 6],
+            [true, 0],
+        ];
+    }
+}
diff --git a/tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php b/tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php
index bc2c16dc..4105c91c 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php
@@ -73,9 +73,22 @@ class RowCellIteratorTest extends TestCase
     public function testSeekOutOfRange(): void
     {
         $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
+        $this->expectExceptionMessage('Column A is out of range');
 
         $iterator = new RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
-        $iterator->seek(1);
+        self::assertFalse($iterator->getIterateOnlyExistingCells());
+        self::assertEquals(2, $iterator->getCurrentColumnIndex());
+        $iterator->seek('A');
+    }
+
+    public function testSeekNotExisting(): void
+    {
+        $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
+        $this->expectExceptionMessage('Cell does not exist');
+
+        $iterator = new RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
+        $iterator->setIterateOnlyExistingCells(true);
+        $iterator->seek('B');
     }
 
     public function testPrevOutOfRange(): void