I would not use Tint. It's slow. It even warns against overuse in the docs.
Create 3 pictures (primary colors), and use a randomizing algorithm to turn them on & off.
Each picture (Red, Yellow, Blue) should be mostly transparent. Depending on how combined, this will give you 8 colors. (Red, Yellow, Blue, Orange, Green, Magenta, White, Clear(no picture))
Be Well