Unless you can find a 'close enough' touch up color in an auto parts store - You will likely have to buy (or at least pay for) more than 1 oz. I don't know what the minimum mix quantity is, but I would think about a pint. I have never bought less than a quart myself. Even the touch ups are not cheap, so might be worth it to buy a small can vs. try several wrong colors if not sure what to get. What color are you trying to match?
