I just finished a GB Cap 232. a few weeks ago.
I had the same color matching issue, so I also used latex paint.
To fuel proof the paint. I bought a rattle can of clear coat from the auto parts store O'Riely's (sp?). and put one coat over the latex.
I then. used a rattle can of the lusterkote clear coat on top of that.
It worked great.
you do need to wait at least a week, maybe two after painting before you fly. It takes a long time for the laytex paint to dry, especially if it is exterior paint.

Hope this helps.