If you're gonna use no stabilized resin try putting a drop or two of blue tint in it. Painters frequently due this to keep whites from yellowing.
It may or may not help, but it is worth a try.
Thanks, to be honest when it comes to proper boards ill buy the dearer stuff for the cosmetics. Just keen to get the first few experimental boards done without breaking the bank. The cosmetics don't matter, as long as the resin performs ok.
Given the purple/red cast of cheapo resin, why not just add a little red tint so it looks intentional?