diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 4a4e345a9..a03a95d9e 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -361,9 +361,9 @@ Colorize the textures with the given color.
 it is an int, then it specifies how far to interpolate between the
 colors where 0 is only the texture color and 255 is only `<color>`. If
 omitted, the alpha of `<color>` will be used as the ratio.  If it is
-the word "`alpha`", then the alpha of the color will be multiplied with
-the alpha of the texture with the RGB of the color replacing the RGB of
-the texture.
+the word "`alpha`", then each texture pixel will contain the RGB of
+`<color>` and the alpha of `<color>` multiplied by the alpha of the
+texture pixel.
 
 Sounds
 ------