When last we'd met, I'd finished the red undercoat of my Phoenix, and was contemplating the application of the white accents. I should have done some more contemplating.
The red undercoat has bloomed through the white and made a lovely purple tone. I quite like the purple; it reminds me of some flowers my mother planted in the back yard of the house where I grew up. What it does not remind me of is the white accent color of the rest of my army.
Two possible causes of this debacle: the paint siphon cup that I'm using is stained with the red I've been using as a basecoat, and the red pigments are mixing with the white; or, the solvents in the cheap airbrush paint I've been using are dissolving the lower layers, and causing the red pigments to bloom through. The test is simple. I've replaced the small siphon cup I'd been using with one of my larger glass siphon bottles, and put down another layer of blue. If that stays blue, then the siphon cup was the culprit. If not, then I brush on a layer of varnish, then blue, before I return to airbrushing the white.
Either way, gigantic hassle, but not unexpected: I constantly experiment with new techniques. Sometimes they come out terribly! With luck, the blue I've just put down will be the fix we need - if so, I'll post pictures soon.