diff --git a/chess/__init__.py b/chess/__init__.py
index 0604cec54..65719fd5c 100644
--- a/chess/__init__.py
+++ b/chess/__init__.py
@@ -29,7 +29,8 @@
 
 Color = bool
 COLORS = [WHITE, BLACK] = [True, False]
-COLOR_NAMES = ["black", "white"]
+ColorName = Literal["white", "black"]
+COLOR_NAMES: List[ColorName] = ["black", "white"]
 
 PieceType = int
 PIECE_TYPES = [PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING] = range(1, 7)