ive played like 100+ matches online casual and ranked and i was always using default colors til i realized i could select all 4. so uh yeah i guess just keep picking those dudes a bunch of times
Okay, I found out more about how exactly to unlock colors:
in arcade mode you have to finish a total of 5 matches to get a single color (5 matches for color 3 and 5 other matches for color 4). You can then exit after the 5th game and get the color, or if you played 7 games you can exit after the 3rd one and get the other color.
I’m unsure of the number of matches required to unlock a color online, but it’s higher than 5. Lobby matches don’t seem to count.
the number of matches in online and arcade don’t seem to stack, i.e. if you played 9 arcade matches and 1 online match you won’t get the color.
Lobby matches do in fact count. Not sure how many but after a 50 match set in a lobby I unlocked colors 3 and 4 for captain marvel and someone else I was randomly picking. Don’t remember who