I voted blue, but I believe it depends on the civilization. Saracens, for example. I would never like any color more than Green for them.
Same for blue for Romans and Byzantines.
Also, more colors would be cool
Red all the way since AoE 1.
I like teal. Sadly it was never an option >->
Thanks #aoe3 for letting us change colors as we like c:
Green and purple are my two favorite colors IRL, so they’re the two I use the most in-game.
Green, followed by Cyan/Teal.
Orange - my favourite colour anyway. And I really like the shade of Orange in game.
Sadly sometimes the orange colour blends in with the environment too much, but oh well!
Grey for me, though mostly because there will never be a campaign that pits you in the colour, so it feels like an underdog of sorts.