Randy,
I agree with the theory, However I don't like the idea of sanding color with 1500. The finest I would recommend sanding color coats with is 800 or possibly 1200 and never, NEVER sand any color that has metallic or pearl in it ( or candy for that matter)
The problem I have with sanding that fine on color coats is , the tendency in our world is to put on light coats, with 1500 grit scratches, you don't gain any mechanical tooth . When you spray light layers with lacquer, you are depending upon mechanical tooth to hold the coat in place until you "flood" it with clear to melt it all together/ The particles of paint that hit the surface can actually bridge over the scratch and form non adhesive areas. I would much rather see a slightly larger scratch pattern to insure mechanical grip for subsequent layers. Bopttom line, unless you are spraying pearls, you wont see an 800 grit scratch. In fact, I prep sand with 400 dry a lot of times. The only advantage that I can see to using finer grits ( read that 1200 or 1500 ) is that you wont sand through the color.
Remember with lacquer, you must get solvent penetration in order to have good adhesion. However, this solvent penetration can come from later coats as the solvent will push all the way to the base and then back out if there is enough solvent, and enough time. This is why every coat you spray brings back those darn imperfections that you so carefully sanded away ( that is if you pound on the coats to fast or to heavy)