--- a/TranslucentColor.st	Wed Jan 31 13:14:00 2018 +0100
+++ b/TranslucentColor.st	Wed Jan 31 13:15:13 2018 +0100
@@ -190,6 +190,8 @@
 !TranslucentColor methodsFor:'comparing'!
 
 = aColor
+    aColor species == self species ifFalse:[^ false].
+
     ^ (self alpha = aColor alpha)
       and:[ super = aColor ]
 !