I posted a picture of a Fiesta Yellow mini in the resto thread, it's a subtle yellow that I think would suit the style and the period well. As for its clashing with the red trim, no more so than Cactus clashes with Olive as in Nick1854's 1300.
The 1300 came in a pale yellow, jasmine if i remember correctly. I can't remember the interior colour but i know i have a pic of one somewhere. It's a nice colour but it's white for me!
