The devs could give us an option to apply a color filter to the game to let the player adjust the graphics to their liking

Age of Empires IV IV - Discussion
1

This solves the problem with those who like the graphics as they are and those who want more grimdark colors.

I like the trailer graphics because it gives clarity to gameplay and I have trouble distinguishing between colors.

Those who don’t like the cartoony colors and want more realistic graphics should be given the choice to change it.

2

Replace the 3D art style can be nice too.