To unlock more costume colors on the PC, PS3, or Xbox 360 you need to beat certain time attack and survival modes in the Challenge section.
The extra colors for the character costumes don’t have to be unlocked for each character, you just have to unlock the color number and it is available for all characters.
To unlock the colors, beat the following challenges on any difficulty:
- Color 3: Time Attack Level 1
- Color 4: Survival Level 1
- Color 5: Time Attack Level 6
- Color 6: Survival Level 6
- Color 7: Time Attack Level 11
- Color 8: Survival Level 11
- Color 9: Time Attack Level 16
- Color 10: Survival Level 16