Fix function-no-unknown false positives for SCSS functions with namespace

.changeset/brave-balloons-rescue.md

@@ -0,0 +1,5 @@
+---
+"stylelint": patch
+---
+
+Fixed: `function-no-unknown` false positives for SCSS functions with namespace

lib/rules/function-no-unknown/__tests__/index.js

@@ -28,6 +28,10 @@ testRule({
 		{
 			code: 'a { height: calc(10px*(5*(10 - 5))); }',
 		},
+		{
+			code: 'a { transform: color.adjust(1px); transform: rgb(color.adjust(1px)); }',
+			description: 'ignore scss namespaced functions',
+		},
 	],
 
 	reject: [

lib/utils/isStandardSyntaxValue.js

@@ -26,6 +26,11 @@ module.exports = function isStandardSyntaxValue(value) {
 		return false;
 	}
 
+	// SCSS namespace (example namespace.function-name())
+	if (/^.+\.[-\w]+\(/.test(value)) {
+		return false;
+	}
+
 	// Less variable
 	if (normalizedValue.startsWith('@')) {
 		return false;