Bob, when I started painting in the 70's, Dupont Imron was the logical choice because it was the name customers recognized from reading bicycle magazines. There was a paint store near me that carried Dupont products so Imron was easy for me to get. There wasn't a PPG supplier close by so I didn't then or now know much about them. Imron's paint chip catalog had lots of non metallic options (as well as metallics too). In the 80's I started using House of Kolor to get the glamor pearl and candy colors. They have continued to evolve over the years. They now have primers in the primary colors (as well as black and white) which are wonderful to use as a foundation so that if the paint chips, the base coats look similar in color to the top coat color. These primer colors can also be thinned to work as sealers (used to provide an even undercoat color over the sanded primers that also increases adhesion). In fact you can probably mix those primary colors to be close to the green you are looking for (and go straight to clears).

The other change recently (if a few years ago can be described as "recent") is that what H of K does (instead of supplying a quart of one color), is sell the tinting colors in much smaller amounts and you mix them together to get the effect you want. Now when I look at their color chart, I get a formula instead of a color #. I then buy little cans of concentrated colors required by the formula and mix it myself in the suggested ratio. Of course I can alter the ratio a bit to get the effect I want. Because of their primers and the mix it yourself colors, all my old colleagues like to use House of Kolor products (except all of us old timers like to use Dupont Imron for our final clears).

I realize that the convenience of your local supplier and what they carry is why you choose a paint brand. I have also found that my local suppliers are not helpful when it comes to asking for advice. The guys that work there don't necessarily have painting experience.. What I do is network with other experienced frame painters when I have questions.