RAL is a european colour standard - IE RAL 7025 is the same dark grey anywhere. It's an industry standard, so you can get RAL 7025 2k, celly, enamel and even powder coat, and they will all be very close to the same colour.
Aim for a primer that is similar in colour to the topcoat, but don't go mad. 2k covers pretty well, so the main thing is to just get all the primer the same colour, and nice and flat.
If I was faced with a mini in all sorts of colours, I would ~400 grit it all back and put a coat of high build primer on, then a light dusting of an aerosol can as a "guide coat" then use more 400 grit to flat this back, with the guide coat showing any high or low spots that need attention. I'd probably have to do this stage 2 or 3 times, and then flat back with ~600 before the final colour.
Remember your 2k safe mask, and good ventilation. The stuff IS poisonous, but the amount you'll ingest is a lot less than will cause an issue in 99% of people.
Practice on some spare panels first, to get your gun and mix setup right, and make sure the paint doesn't affect you. I've never known it to, but then again people are allergic to all sorts of things. Most people can eat scampi and chips, but if I do, my throat itches and my tongue swells up. If you have any worries, just use cellulose instead. It smells nicer, is easier to flat but it takes ages to harden fully, and is never going to be as durable as a 2k job.
edit: The paint on that mini is a pearlescent finish. Like a metallic, it needs lacquering and is going to be hard work to spray. I'd recommend sticking to a non metallic colour for your first go.
well it doesn't need to be sprayed until Xmas & I've got the gun, compressor etc coming through the post and plan on starting the spraying after all the rusted patched are fiber glassed & welded. (there's only a small amount on the passenger side floor & I've fiber glassed over it to give the outside a smooth look but will weld the inside as i have been told without this the car will fail its MOT)
I think ill still use 2k & buy a mask & paint suit, that way ill never have to find out if I'm allergic or not
would you not use a lacquer after the colour has gone on?
ah thats great news! RAL 5002 (the colour i want) is flat! whats the best way to get it shiny as hell? a really good machine wax & polish?
