Pigment discoloration on repairs?

General Discussion
1

We were working on this board the other day - it’s a spray-painted PU blank with poly resin - we matched the pigment pretty well and tested it on some paper and when cured it looked good, so we put it on the board…

 

…then, not really sure what exactly happened, but while curing the color of the pigment that was on the board shifted from a nicely matching neon yellow/green to a terrible, brownish mustard-yellow/orange - anyone have any ideas what could’ve happened in the curing process that made the color show up differently on the board than on the paper? We’ve been scratching our heads all day trying to think where this one went wrong - my guess was it may be showing up darker for the same reason tinted lap lines show up darker (color over color instead of color over white), but the pigment we used is fairly opaque so we shouldn’t be seeing too much light passing through it? 

Hopefully some of you experienced painters/tinters have some advice for us!

2

How deep is the repair? It’s been my experience that  masses of pigmented resin will shift toward a darker shade when used as filler. Also, was there any thickener involved (cabosil, q cell, enfamil, talc, flour, etc)

3

Repair wasn’t too deep - I’ll have to double-check with my partner on whether or not he used q-cell but I’m sure he did at least a little filling - it was really just a split in the glass, not too much of an indent in it. I’m pretty sure he would’ve done the filler without pigment and just did pigment in the lam and sanding coats, but you could be onto something there