This is interesting to me, as that's my least favorite chip of the set, but it also made almost all my decisions for pairing denoms with colors. I find myself generally disappointed in CPC's shades of yellow, and finding two shades that i both liked and sufficiently contrasted was essentially impossible. That's why it's the 25k chip - it will see the least amount of play. That also all but forced the blue into the 5k slot, orange into the 1k slot, and purple into the 500 slot. The only question left was what to do with green/red, and I wasn't about to have the 100 chip be green since green is nearly synonymous with the 25 chip.
I'm a big fan of orange (Syracuse alum) however my eyes are drawn to the yellow. Its the shades you used that make it professional looking without having a super bright canary yellow glow. Funny that its your least favorite