diff --git a/src/Interfaces/ColorInterface.php b/src/Interfaces/ColorInterface.php
index 07ee8e91..2662258d 100644
--- a/src/Interfaces/ColorInterface.php
+++ b/src/Interfaces/ColorInterface.php
@@ -11,4 +11,5 @@ interface ColorInterface
     public function toArray(): array;
     public function toHex(string $prefix = ''): string;
     public function toInt(): int;
+    public function isGreyscale(): bool;
 }