Anyone know the innards of the gitk program?

I knew that gitk is written in a scripting language, so I had high hopes of making a 
little tweak to it.  But, alas, it's 12000 lines of languages I don't know!

The farthest I got was finding “text $cflist \” on line 2381 and the corroborating comment 
“# lower right” just above it.

What I want to accomplish is to highlight specific words in the Patch view; in particular 
certain path element names to indicate files I'm specifically interested in reviewing and 
those that I'm specifically not at all interested in.

Considering the way it works — Tk widgets — that ought to be easy.  I've used Perl/Tk in 
the past and can look up the parameters to different element types.  But I have no idea 
where to put such a change, or the general flow of the program in general.

Is anyone knowledgeable in the inner workings of this program willing to help me out?

I've tried a few git repository GUI programs (on Windows) and always end up gravitating 
back to Git Gui and gitk !

—John