On the Character Select screen, highlight the Character of your 
choice, hold Start and press Block (C Left or the Z Button) up 
to three times to find up to three different styles or colors of 
clothes for the Character you chose. Most Characters only have 
two different outfits, but some have up to three. 

For example: With Johnny Cage, if you hold Start and press 
Block once, you will find his red outfit. Hold Start and press 
Block twice to find his blue outfit (his default one) or hold 
Start and press Block three times to find him wearing a tuxedo.