Many thanks for sharing your secrets to the Dreaded Yellow, ericr!
Unfortunately, I use acrylics, so I may stay challenged. My own research shows that a light gray primer (model masters) works better than either tan or white. One day I should see how sand (lighter than tan) works. I've taken to pouring off a fair bit of excess carrier which seems to help, but I'm not so sure how this info will translate over into the very different world of Enamels.
Gratefully,
Brian da Basher