diff --git a/src/Value/Color.php b/src/Value/Color.php
index a084fd35..5b54ce45 100644
--- a/src/Value/Color.php
+++ b/src/Value/Color.php
@@ -71,14 +71,21 @@ public static function parse(ParserState $oParserState, bool $bIgnoreCase = fals
             $oParserState->consume('(');
 
             $bContainsVar = false;
-            $iLength = $oParserState->strlen($sColorMode);
+            if ($sColorMode === 'rgb') {
+                $sColorTarget = 'rgba';
+            } elseif ($sColorMode === 'hsl') {
+                $sColorTarget = 'hsla';
+            } else {
+                $sColorTarget = $sColorMode;
+            }
+            $iLength = $oParserState->strlen($sColorTarget);
             for ($i = 0; $i < $iLength; ++$i) {
                 $oParserState->consumeWhiteSpace();
                 if ($oParserState->comes('var')) {
-                    $aColor[$sColorMode[$i]] = CSSFunction::parseIdentifierOrFunction($oParserState);
+                    $aColor[$sColorTarget[$i]] = CSSFunction::parseIdentifierOrFunction($oParserState);
                     $bContainsVar = true;
                 } else {
-                    $aColor[$sColorMode[$i]] = Size::parse($oParserState, true);
+                    $aColor[$sColorTarget[$i]] = Size::parse($oParserState, true);
                 }
 
                 if ($bContainsVar && $oParserState->comes(')')) {
@@ -88,7 +95,14 @@ public static function parse(ParserState $oParserState, bool $bIgnoreCase = fals
 
                 $oParserState->consumeWhiteSpace();
                 if ($i < ($iLength - 1)) {
-                    $oParserState->consume(',');
+                    if ($oParserState->comes(',')) {
+                        $oParserState->consume(',');
+                    } elseif ($oParserState->comes('/')) {
+                        $oParserState->consume('/');
+                    } elseif ($oParserState->comes(')')) {
+                        // No alpha channel information
+                        break;
+                    }
                 }
             }
             $oParserState->consume(')');
@@ -163,7 +177,7 @@ public function render(OutputFormat $oOutputFormat)
                 $this->aComponents['b']->getSize()
             );
             return '#' . (($sResult[0] == $sResult[1]) && ($sResult[2] == $sResult[3]) && ($sResult[4] == $sResult[5])
-                    ? "$sResult[0]$sResult[2]$sResult[4]" : $sResult);
+                ? "$sResult[0]$sResult[2]$sResult[4]" : $sResult);
         }
         return parent::render($oOutputFormat);
     }
diff --git a/tests/ParserTest.php b/tests/ParserTest.php
index 2c1c7287..8832a661 100644
--- a/tests/ParserTest.php
+++ b/tests/ParserTest.php
@@ -164,7 +164,9 @@ public function colorParsing(): void
             . 'background-color: rgb(255,var(--rg));background-color: hsl(var(--some-hsl));}'
             . "\n"
             . '#variables-alpha {background-color: rgba(var(--some-rgb),.1);'
-            . 'background-color: rgba(var(--some-rg),255,.1);background-color: hsla(var(--some-hsl),.1);}',
+            . 'background-color: rgba(var(--some-rg),255,.1);background-color: hsla(var(--some-hsl),.1);}'
+            . "\n"
+            . '#css4-rgba {background-color: rgba(242,245,249,45%);background-color: #f2f5f9;}',
             $oDoc->render()
         );
     }
diff --git a/tests/fixtures/colortest.css b/tests/fixtures/colortest.css
index f834aa77..41c5d223 100644
--- a/tests/fixtures/colortest.css
+++ b/tests/fixtures/colortest.css
@@ -27,3 +27,8 @@
 	background-color: rgba(var(--some-rg), 255, 0.1);
 	background-color: hsla(var(--some-hsl), 0.1);
 }
+
+#css4-rgba {
+	background-color: rgb(242 245 249 / 45%);
+	background-color: rgba(242 245 249);
+}