I think this can be easily achieved by mixing colortone vintage amber with a few drops of cherry red, and I mean just barely enough to give it a SMALL red tint in with a 90/10 nitro. spray that, mix up a bit of blue and red until you get the purple you want and burst that on. working very so gently from the out side in. Of course have a good base of about 10 cotes before.....those cheap guns from harbor freight are perfect. best thing is once they crap out you can just toss them and go buy another without feeling bad. Test it on some scrap first, I think you will find its a lot easier than you are building it up to be. It just takes patience.