Like the original comments by the Apple engineers in the source indicate, you get the best results by changing the Terminal window settings to white on black (also change the text color of bold text for this version!)
Update: after reading the page of QuickASCII, an open source project geared at improving ASCIIMoviePlayer, I decided to try GLTerm, since they suggested it was faster than Terminal.app. And sure, it's a *LOT* faster. Now I can play movies in color almost at full speed! Woohoo :)
Jonas (remove the SPAM, ME and NOT to mail me).