I too have accepted that I'll never have anything on the FP or have one of my treasuries chosen for the FP for the same reason - etsy's apparent dislike of color at all, let alone bright, vibrant color.
I tried the white backgrounds on photos and didn't like it at all so I went back to my more "interesting" non-white backgrounds.
I can't believe that etsy wants not only white backgrounds for the FP but generally, imo, very boring treasuries: monochromatic, neutral colors. That's just not who I am at all - in fact I'm the opposite of that.
So when all is said and done, best to be true to yourself. Maybe someday the person or people choosing FP treasuries will be a color freak like we are!