Raises an interesting point - Logan is dark and serious and still is on par with DP for being X-Comic material. Exception that proved the rule?
Comics aren't a tone, they're a medium. Saying they all need humor is like saying Popsicles can only come in raspberry.
It wasn’t Fox so much as Bryan Singer who thought the colorful costumes would look silly. At the time, he probably was right. After X2, they just went with the dark look.
But he was also the one that came full circle, and brought the colorful costumes back for "Apocalypse".
I agree and that’s probably because of the success of the MCU and then immediately abandoned it in DP. It’s a real shame. Also, I think Singer was just a producer on Apocalypse. Could be wrong.