diff --git a/CHANGELOG.md b/CHANGELOG.md
index bf3db03a..13d94fe3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ Please also have a look at our
     - `rgb` and `rgba`, and `hsl` and `hsla` are now aliases (#797}
     - Parse color functions that use the "modern" syntax (#800)
     - Render RGB functions with "modern" syntax when required (#840)
+    - Support `none` as color function component value (#859)
 - Add a class diagram to the README (#482)
 - Add more tests (#449)
 
diff --git a/src/Value/Color.php b/src/Value/Color.php
index 8b913d54..c4d6a4ee 100644
--- a/src/Value/Color.php
+++ b/src/Value/Color.php
@@ -116,15 +116,20 @@ private static function parseColorFunction(ParserState $parserState): CSSFunctio
         }
 
         $containsVar = false;
+        $containsNone = false;
         $isLegacySyntax = false;
         $expectedArgumentCount = $parserState->strlen($colorModeForParsing);
         for ($argumentIndex = 0; $argumentIndex < $expectedArgumentCount; ++$argumentIndex) {
             $parserState->consumeWhiteSpace();
+            $valueKey = $colorModeForParsing[$argumentIndex];
             if ($parserState->comes('var')) {
-                $colorValues[$colorModeForParsing[$argumentIndex]] = CSSFunction::parseIdentifierOrFunction($parserState);
+                $colorValues[$valueKey] = CSSFunction::parseIdentifierOrFunction($parserState);
                 $containsVar = true;
+            } elseif (!$isLegacySyntax && $parserState->comes('none')) {
+                $colorValues[$valueKey] = $parserState->parseIdentifier();
+                $containsNone = true;
             } else {
-                $colorValues[$colorModeForParsing[$argumentIndex]] = Size::parse($parserState, true);
+                $colorValues[$valueKey] = Size::parse($parserState, true);
             }
 
             // This must be done first, to consume comments as well, so that the `comes` test will work.
@@ -139,10 +144,10 @@ private static function parseColorFunction(ParserState $parserState): CSSFunctio
                 break;
             }
 
-            // "Legacy" syntax is comma-delimited.
+            // "Legacy" syntax is comma-delimited, and does not allow the `none` keyword.
             // "Modern" syntax is space-delimited, with `/` as alpha delimiter.
             // They cannot be mixed.
-            if ($argumentIndex === 0) {
+            if ($argumentIndex === 0 && !$containsNone) {
                 // An immediate closing parenthesis is not valid.
                 if ($parserState->comes(')')) {
                     throw new UnexpectedTokenException(
@@ -291,7 +296,8 @@ private function renderAsHex(): string
     }
 
     /**
-     * The "legacy" syntax does not allow RGB colors to have a mixture of `percentage`s and `number`s.
+     * The "legacy" syntax does not allow RGB colors to have a mixture of `percentage`s and `number`s,
+     * and does not allow `none` as any component value.
      *
      * The "legacy" and "modern" monikers are part of the formal W3C syntax.
      * See the following for more information:
@@ -306,6 +312,10 @@ private function renderAsHex(): string
      */
     private function shouldRenderInModernSyntax(): bool
     {
+        if ($this->HasNoneAsComponentValue()) {
+            return true;
+        }
+
         if (!$this->colorFunctionMayHaveMixedValueTypes($this->getRealName())) {
             return false;
         }
@@ -337,6 +347,11 @@ private function shouldRenderInModernSyntax(): bool
         return $hasPercentage && $hasNumber;
     }
 
+    private function hasNoneAsComponentValue(): bool
+    {
+        return \in_array('none', $this->aComponents, true);
+    }
+
     /**
      * Some color functions, such as `rgb`,
      * may have a mixture of `percentage`, `number`, or possibly other types in their arguments.
diff --git a/tests/Unit/Value/ColorTest.php b/tests/Unit/Value/ColorTest.php
index 5c502f82..f516d313 100644
--- a/tests/Unit/Value/ColorTest.php
+++ b/tests/Unit/Value/ColorTest.php
@@ -114,12 +114,18 @@ public static function provideValidColorAndExpectedRendering(): array
                 'rgb(0% 60% 0%)',
                 'rgb(0%,60%,0%)',
             ],
-            /*
-            'modern rgb with none' => [
+            'modern rgb with none as red' => [
                 'rgb(none 119 0)',
                 'rgb(none 119 0)',
             ],
-            //*/
+            'modern rgb with none as green' => [
+                'rgb(0 none 0)',
+                'rgb(0 none 0)',
+            ],
+            'modern rgb with none as blue' => [
+                'rgb(0 119 none)',
+                'rgb(0 119 none)',
+            ],
             'modern rgba with fractional alpha' => [
                 'rgb(0 119 0 / 0.5)',
                 'rgba(0,119,0,.5)',
@@ -148,12 +154,10 @@ public static function provideValidColorAndExpectedRendering(): array
                 'rgb(0% 60% 0% / 50%)',
                 'rgba(0%,60%,0%,50%)',
             ],
-            /*
             'modern rgba with none as alpha' => [
                 'rgb(0 119 0 / none)',
-                'rgba(0 119 0 / none)',
+                'rgba(0 119 0/none)',
             ],
-            //*/
             'legacy rgb with var for R' => [
                 'rgb(var(--r), 119, 0)',
                 'rgb(var(--r),119,0)',
@@ -310,22 +314,26 @@ public static function provideValidColorAndExpectedRendering(): array
                 'hsl(120 100% 25%)',
                 'hsl(120,100%,25%)',
             ],
-            /*
-            'modern hsl with none' => [
+            'modern hsl with none as hue' => [
                 'hsl(none 100% 25%)',
                 'hsl(none 100% 25%)',
             ],
-            //*/
+            'modern hsl with none as saturation' => [
+                'hsl(120 none 25%)',
+                'hsl(120 none 25%)',
+            ],
+            'modern hsl with none as lightness' => [
+                'hsl(120 100% none)',
+                'hsl(120 100% none)',
+            ],
             'modern hsla' => [
                 'hsl(120 100% 25% / 0.5)',
                 'hsla(120,100%,25%,.5)',
             ],
-            /*
             'modern hsla with none as alpha' => [
-                'hsl(120 100% 25% none)',
-                'hsla(120 100% 25% none)',
+                'hsl(120 100% 25% / none)',
+                'hsla(120 100% 25%/none)',
             ],
-            //*/
         ];
     }
 
@@ -386,6 +394,18 @@ public static function provideInvalidColor(): array
                 'rgb(255, 0px, 0)',
             ],
             //*/
+            'legacy rgb color with none as red' => [
+                'rgb(none, 0, 0)',
+            ],
+            'legacy rgb color with none as green' => [
+                'rgb(255, none, 0)',
+            ],
+            'legacy rgb color with none as blue' => [
+                'rgb(255, 0, none)',
+            ],
+            'legacy rgba color with none as alpha' => [
+                'rgba(255, 0, 0, none)',
+            ],
             'modern rgb color without slash separator for alpha' => [
                 'rgb(255 0 0 0.5)',
             ],
@@ -407,6 +427,18 @@ public static function provideInvalidColor(): array
             'legacy hsl color with 5 arguments' => [
                 'hsl(0, 100%, 50%, 0.5, 0)',
             ],
+            'legacy hsl color with none as hue' => [
+                'hsl(none, 100%, 50%)',
+            ],
+            'legacy hsl color with none as saturation' => [
+                'hsl(0, none, 50%)',
+            ],
+            'legacy hsl color with none as lightness' => [
+                'hsl(0, 100%, none)',
+            ],
+            'legacy hsla color with none as alpha' => [
+                'hsl(0, 100%, 50%, none)',
+            ],
             /*
             'legacy hsl color without % for S/L units' => [
                 'hsl(0, 1, 0.5)'