Would be almost right.... RED on JP is pretty much a full cab spray... youd only need 1 ltr each colour id say... you dont want big thick levels of paint... is all done thinly and you should be able to cover all the red in 2 light sprays... you never keep spraying till you see a solid colour as you use a ton of paint unnecessarily.
1 light coat.. allow to almost dry.. then another light coat is all you need