There's gotta be a better way than that. If he has to test 40 links on 1 page... that'll too many image maps (at least for me). What I'd do is check the properties of the text for anything that resembles a colour property (colour, RGB, CMY, etc.). Now that I think about it though, it seems unlikely (I'm running a rather large script right now, so I'll check Monday). You may want to have the script open up the source code for the file you have and see if it has the properties correctly coded after the link.
If both of those possibilities fail, then yes, I would go with Bitmap checks for sure.