diff --git a/src/wp-includes/kses.php b/src/wp-includes/kses.php
index 062f85308512f..094b6c4724907 100644
--- a/src/wp-includes/kses.php
+++ b/src/wp-includes/kses.php
@@ -2756,6 +2756,27 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
 		'list-style-image',
 	);
 
+	/*
+	 * CSS attributes that accept rgb(a) color data types.
+	 */
+	$css_color_data_types = array(
+		'color',
+
+		'border',
+		'border-color',
+		'border-right',
+		'border-right-color',
+		'border-bottom',
+		'border-bottom-color',
+		'border-left',
+		'border-left-color',
+		'border-top',
+		'border-top-color',
+
+		'background',
+		'background-color',
+	);
+
 	/*
 	 * CSS attributes that accept gradient data types.
 	 *
@@ -2779,6 +2800,7 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
 		$css_test_string = $css_item;
 		$found           = false;
 		$url_attr        = false;
+		$color_attr      = false;
 		$gradient_attr   = false;
 		$is_custom_var   = false;
 
@@ -2798,6 +2820,7 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
 				$found         = true;
 				$url_attr      = in_array( $css_selector, $css_url_data_types, true );
 				$gradient_attr = in_array( $css_selector, $css_gradient_data_types, true );
+				$color_attr    = in_array( $css_selector, $css_color_data_types, true );
 			}
 
 			if ( $is_custom_var ) {
@@ -2840,6 +2863,20 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
 			}
 		}
 
+		if ( $found && $color_attr ) {
+			// Simplified: matches the sequence `rgb(*)` or `rgba(*)`.
+			$comma_syntax = '/rgba?\(\s*([+-]?\d*\.?\d+)(%)?\s*,\s*([+-]?\d*\.?\d+)(%)?\s*,\s*([+-]?\d*\.?\d+)(%)?\s*(?:,\s*([+-]?\d*\.?\d+)(%)?\s*)?\)/i';
+			$space_syntax = '/rgba?\(\s*([+-]?\d*\.?\d+)(%)?\s+([+-]?\d*\.?\d+)(%)?\s+([+-]?\d*\.?\d+)(%)?\s*(?:\/\s*([+-]?\d*\.?\d+)(%)?\s*)?\)/i';
+
+			preg_match_all( $comma_syntax, $parts[1], $color_matches_comma );
+			preg_match_all( $space_syntax, $parts[1], $color_matches_space );
+
+			foreach ( array_merge( $color_matches_comma[0], $color_matches_space[0] ) as $color_match ) {
+				// Remove the whole `rgb(*)` or `rgba(*)` bit that was matched above from the CSS.
+				$css_test_string = str_replace( $color_match, '', $css_test_string );
+			}
+		}
+
 		if ( $found ) {
 			/*
 			 * Allow CSS functions like var(), calc(), etc. by removing them from the test string.
diff --git a/tests/phpunit/tests/kses.php b/tests/phpunit/tests/kses.php
index dc01b5dfe2979..3c9b87c86456d 100644
--- a/tests/phpunit/tests/kses.php
+++ b/tests/phpunit/tests/kses.php
@@ -1203,15 +1203,30 @@ public function data_safecss_filter_attr() {
 				'css'      => 'height: expression( body.scrollTop + 50 + "px" )',
 				'expected' => '',
 			),
-			// RGB color values are not allowed.
+			// RGBA background color are allowed.
 			array(
-				'css'      => 'color: rgb( 100, 100, 100 )',
-				'expected' => '',
+				'css'      => 'background-color: rgba(0,0,0,0)',
+				'expected' => 'background-color: rgba(0,0,0,0)',
 			),
-			// RGBA color values are not allowed.
 			array(
-				'css'      => 'color: rgb( 100, 100, 100, .4 )',
-				'expected' => '',
+				'css'      => 'background-color: rgba(0, 0, 0, 0)',
+				'expected' => 'background-color: rgba(0, 0, 0, 0)',
+			),
+			array(
+				'css'      => 'background-color: rgba(100, 100, 100, 0)',
+				'expected' => 'background-color: rgba(100, 100, 100, 0)',
+			),
+			array(
+				'css'      => 'background-color: rgba(10%, 10%, 10%, 0)',
+				'expected' => 'background-color: rgba(10%, 10%, 10%, 0)',
+			),
+			array(
+				'css'      => 'background-color: rgba(0, 0, 0, 0.1)',
+				'expected' => 'background-color: rgba(0, 0, 0, 0.1)',
+			),
+			array(
+				'css'      => 'background-color: rgba(0, 0, 0, .1)',
+				'expected' => 'background-color: rgba(0, 0, 0, .1)',
 			),
 			// Allow min().
 			array(
@@ -1333,6 +1348,86 @@ public function data_safecss_filter_attr() {
 				'css'      => 'gap: 10px;column-gap: 5px;row-gap: 20px',
 				'expected' => 'gap: 10px;column-gap: 5px;row-gap: 20px',
 			),
+			// RGB color.
+			array(
+				'css'      => 'color: rgb(255, 0, 0)',
+				'expected' => 'color: rgb(255, 0, 0)',
+			),
+			array(
+				'css'      => 'color: rgb(255 0 0)',
+				'expected' => 'color: rgb(255 0 0)',
+			),
+			array(
+				'css'      => 'color: rgb(100%, 0%, 50%)',
+				'expected' => 'color: rgb(100%, 0%, 50%)',
+			),
+			array(
+				'css'      => 'color: rgb(255 50% 0)',
+				'expected' => 'color: rgb(255 50% 0)',
+			),
+			// RGBA color.
+			array(
+				'css'      => 'color: rgba(255, 128, 0, 0.5)',
+				'expected' => 'color: rgba(255, 128, 0, 0.5)',
+			),
+			array(
+				'css'      => 'color: rgb(255 128 0 / 50%)',
+				'expected' => 'color: rgb(255 128 0 / 50%)',
+			),
+			// RGB color with extra whitespace.
+			array(
+				'css'      => 'color: rgb( 255 , 128 , 0 )',
+				'expected' => 'color: rgb( 255 , 128 , 0 )',
+			),
+			// RGB background color.
+			array(
+				'css'      => 'background-color: rgb(200, 100, 50)',
+				'expected' => 'background-color: rgb(200, 100, 50)',
+			),
+			// RGBA border color.
+			array(
+				'css'      => 'border-color: rgba(100, 200, 250, 0.8)',
+				'expected' => 'border-color: rgba(100, 200, 250, 0.8)',
+			),
+			// RGB color in `border` shorthand.
+			array(
+				'css'      => 'border: 1px solid rgb(0, 0, 0)',
+				'expected' => 'border: 1px solid rgb(0, 0, 0)',
+			),
+			// RGBA color in `border` shorthand.
+			array(
+				'css'      => 'border: 1px solid rgba(0, 0, 0, 0.5)',
+				'expected' => 'border: 1px solid rgba(0, 0, 0, 0.5)',
+			),
+			// RGB color in `background` shorthand.
+			array(
+				'css'      => 'background: rgb(0, 0, 0) center',
+				'expected' => 'background: rgb(0, 0, 0) center',
+			),
+			// Malformed RGB color, invalid number of values.
+			array(
+				'css'      => 'color: rgb(255, 128, 0, 0.5, 100)',
+				'expected' => '',
+			),
+			array(
+				'css'      => 'color: rgb(255, 128)',
+				'expected' => '',
+			),
+			// Malformed RGB color, non-numeric values.
+			array(
+				'css'      => 'color: rgb(red, green, blue)',
+				'expected' => '',
+			),
+			// Malformed RGB color, unmatched parentheses.
+			array(
+				'css'      => 'color: rgb(255, 128, 0',
+				'expected' => '',
+			),
+			// Malformed RGB color, empty values.
+			array(
+				'css'      => 'color: rgb(, , )',
+				'expected' => '',
+			),
 			// Margin and padding logical properties introduced in 6.1.
 			array(
 				'css'      => 'margin-block-start: 1px;margin-block-end: 2px;margin-inline-start: 3px;margin-inline-end: 4px;',