Yep, use white decal paper, and trim as required. I have been using white and clear sheets branded 'Experts Choice', from 'Bare Metal Foil Company', who produce the metal foils for bare metal applications. However, I recently discovered a supplier here in the UK, who specialise in virtually all computer papers, and tried theirs. Lo and behold, it's the same stuff, at a third of the cost!
If you're in the USA, then the decal papers from BMFC, as mentioned, and those from Testors, will be the same stuff - different package. But, have a look for a computer supplies company, check their 'Papers' listings, then 'Decal Papers', as you'll probably find a company who can supply at better prices.
EDIT: Forgot to add - not sure where you are, but the only mail-order/internet outlets which come to mind in the USA, apart from local model shops etc, are Squadron, and Sprue Brothers, although I'm sure there will be others. Alternatively, from the UK, there are Hannant's, or direct from Crafty Computer Papers, the latter being my now current source.