How do you change the colour of Mii outfits?

When you unlock the Mech Suit outfit for Mii Brawler it shows a yellow version and a green version. When I try to change the colour it only changes the shirt underneath.

How do you change the colour of anything more than the Mii's shirt?

Mech Suit


Solution 1:

I believe the green mech is for male Miis and the yellow is for female ones. Other than that you can't change it.