Nothing to do with kayaks, but I used a polyester (I'm assuming that's what you're talking about) resin to build an airbox for a snowmobile. There were several coats, and it did have a purplish tint, although it made up the entire thickness....ie: not glassed over wood or anything else....just a mold that made the part entirely of fibreglass. I would imagine that it won't make a really noticeable difference, and if anything shows I think it would just be enough to make it look cool and only another builder would notice the difference. Don't go and use it on my opinion though...wait and see what some of the experts here have to say first. If you use it take a pic and post it. I'd be curious to see how it turned out. Good luck.
James Nixon

: My latest batch of System 3, via Pygmy, has a very definite dark, purple
: color in the part B hardener, vs.the golden honey of previous ones. Pygmy
: says no problem, S3 says "color does not affect properties, and sure
: enough, it seems to set fine, and at least a single coat on a test panel
: doesn't have any noticeable color. Still, I'm curious- any one else seen
: this? Unmixed, it looks like the color of grape jelly, and mixed, kind of
: dirty, but spread out, looks fine. I'm a little concerned about a possible
: color once I build up several fill coats.