As others have said, it's not looked down on. It doesn't necessarily scream new guy either, I've seen a number of experienced players using two tone recently for one reason or another. Although if it's something that you yourself don't like the look of, it may be worth just renting until you can get on the UKARA database. Two-tone guns can often have trouble reselling compared to the same gun in RIF form, even if the two-tone has been painted over.