This Sounds like my mostly failed attempt at a rainbow lens

I got sheet of Clear plastic hand Cut it with my trusty Rusty dremal tool and Applied Drops, Lines, rings and Blobos of Clear Color to the back of the lens... It would have worked if I could have found a Plastic that had a anti-reflective coating.

First lens

I covered the lens with 1/16 inch Strips of Circit Etch Tap (I found some in my junk box) then I removed them one at a time and Applied the ColorDarkest to lightest top to bottom.

2. second try random Blobs

3. Third try Getting Miffed at this point Circles smaller to larger starting in the center and working out towarsds the edge of the display

4. Fourth try Printed a Bunch of Random colors on a Sheet of Overhead film

Color was too washed out on all of them and Display was nearly inpossable to see in sunlight (Mostly because of the glare)