I hope you're not scrapping the baits where you think the colors aren't just right. What's not quite right to you might be gang-busters on the fish. People and fish see things differently.
laminates require some thought...what color will go OVER another well. Darker on top is generally the rule. Keep in mind how transparent that top color is though. Light running thru one color will definitely affect the color under it as transparency in that bottom color increases. Instead of a real clear belly color, try adding a small bit of pearl to it and maybe dip a toothpick in white and add that along with the pearl. The pearl will still let some light go thru it but it will also help create a light block where the top color meets it. When two colors are very dominant colors, try adding the lateral line of black or brown or a heavy green to the top of the belly portion before shooting the top color.
Don't let yourself get discouraged with this. Understanding color doesn't just drop in your lap. You have to play with it and try different things with it to get any kind of understand on how it works. When you get a combination of colors that you thought might have been a working pair but isn't, take a cup of coffee and go sit on the picnic table in the sun and study it. Pay attention to where the colors merge and pay particular attention to how one color is influencing the other at the weld. As a rule, if both colors are transparent and light in color you'll end up with a weakly colored bait....too much light moves thru it. Strengthen the top color up and try again and see where your colors have moved. Sometimes you really have to dicker around with that top color to get where you want it and most of the time its by making the color way stronger than you think it should be. Most baits are relatively thin as compared to a cup of plastic so if you are judging a color in the cup you'll be way off base. Try dropping a spoonful of the suspect color on the back of a mold and let it cool enough to handle then lay it next to the bottom color done the same way. Now lay the two colors together and see how they act together. Often times you can save a lot of plastic and temper doing a work-up like this. I do it all the time.
We all handle plastic different from each other and we all see colors differently too. What may appear as blue to me might look purple to you. A deep yellow to you may come off as an orange to Andrew. That said, I really don't think that there is a true "right" or true "wrong" way to any of this plastic play. I once was driving home from hunting with a buddy on a gravel road and maybe drifted a little too far to the left. He mentioned that I was too far over. I just said that I paid taxes on the whole road. Ya, but you're in the wrong lane he said. I stopped the car and asked him just where the "lanes" were and said that on that old gravel road on a straightaway with nobody coming the other direction I could use any portion I want as long as I moved over and gave any other oncoming traffic the use of their right-of-way. The point here is that we all have ownership that we seldom think about. The molds you buy are yours, so why use just the one side? Flip one over that you aren't using for shooting and work colors on that nice flat that you're not paying any attention to. You will learn a lot about color right there if you do.