Stainless color change

[Aardvark]

I have been clear coating decorative fish for a customer. They are 12 to 48 inches long,made from plasma cut stainless steel, and then given various hues along the fins and gill areas from a torch. Once they are powder coated the blues turn to a copper or purple tint. I have varied the temps from 300 to 375 with a corresponding cure time with no noticeable differences in the finished results. I have used different powder brands and gloss levels and all produce the same results. Am I missing something or is it just a product of the way the powder changes the way the light hits the colors (suggestion from one of the powder reps)?

[Banditperformance]

Have you tried heating just the stainless to the cure temp to see if it's not the stainless itself changing?? I do know clears change the hue just a tad, Almost impossible to make it completely transparant.

[Aardvark]

Yep, and there is no change on the coloration.....I sprayed one with brake cleaner just for S&G and the color changed until the cleaner was gone, and ta dahhh.....The blues came back....So I'm guessing that the difference is in the coatings...