I'm afraid I have to differ with the "yellow only over white" concept. It depends on the type of yellow being used. I just finished the painting on my new twin boom Ephesian with yellow over powder blue primer to give me the tint I wanted and it is a great yellow colorwith a slight green tine. In the sun it will change color from under cloudy conditions. By varying the under coat color you can really play around with different results of tints, quite similar to whether to use gold or silver under a candy apple finish. That's the fun of painting, using all the variables to experiment! and yes, yellow is translucient, as is red, and, "gasp", even some blacks.
Will