diff --git a/ASCII/README.md b/ASCII/README.md
index d2da190..4b2aec1 100644
--- a/ASCII/README.md
+++ b/ASCII/README.md
@@ -6,6 +6,15 @@ ascii (text) convert text to ascii art
 
 img (url) convert an image to ascii art - now in color!
 
+The image plugin uses the 99 color extended irc color set.
+Be sure your plugin supports 99 color output.
+Three presets: fast (default), slow, and insane.
+Sast uses the cie1976 color difference algorithm,
+slow uses the cie_cmc algorithm and insane uses the
+cie2000 algorithm. Which looks best is a matter of preference,
+slower settings generally result in more colorful images
+but take considerably longer to generate a color map.
+
 scroll (url) playback of ansi art files from the web
 
 fontlist to get list of fonts