I think the colors were changed because the new colors (mint & purple) photograph better. The dark green and dark blue edgespots kind of blended into one another, though I think the purple and black edgespots have that same problem. I can see that a darker color for the 100,000 makes them easier to differentiate from the almond 250,000 chips.
x2 - the new darker purples are awesome, not a fan of the lighter green 25ks.
It's funny but the "new" 100k color is very similar to the first sample 100k CPS chip PGI got from the factory. Maybe the paulson guys were watching that thread and saw how awesome the darker purple looked, lol.