diff --git a/README.md b/README.md
index 5ef4949..9887ce1 100644
--- a/README.md
+++ b/README.md
@@ -18,3 +18,5 @@ Need to test on mobile devices etc.
 the player can cheat under certain conditions; if there is only one tile left on a row, the player can flag it and if it is a mine, the row will clear. if not, the player can unflag it and click it. not sure how big a deal this is really. 
 
 game is apparently broken in Safari (not sure which version) and iPhone
+
+colours used are not safe for red-green colourblindness