i had light surface scratches that when painted over it could be saw, so i got 3 500ml tins of primer filler from halfords £6.50 a tin.
and i sprayed the full cabinet with it, and after if dryed i gave it a light sand, then used black satinwood (dulux) and a b&q mini roller set.
so far its turned out ok, i was going to do some graphic art on side of it (just a blue tick with mame)
if you can get some plotter paper and as already said put your design on that then cut it out and you can use some sticky removable adhesive spray ( poundland)
stick just the edges on so you know its straight, then tape aroud inside of letters then spray it as it should go onto the other colour ok, if you want it matched go to a paint auto shop with a sample of colour.
hope this helps