diff --git a/discord/colour.py b/discord/colour.py
index eda2e765..2f36916d 100644
--- a/discord/colour.py
+++ b/discord/colour.py
@@ -5577,7 +5577,7 @@ class Colour:
         }
         
         if theme not in themes_cls:
-            raise TypeError("Theme must be one of \"dark\" and \"light\".")
+            raise TypeError("Theme must be one of \"dark\" or \"light\".")
         
         return cls(themes_cls[theme])