Wavy Gradient

How this effect works

A wavy gradient is a few glowing circles on slow orbits. Each blob is a radial gradient — solid color in the middle, transparent at the edge — drawn in "lighter" blend mode so overlapping blobs add up into new colors. The drift layer moves each blob along its own sine-wave orbit, slightly out of phase with the others, which is what makes the whole thing breathe instead of spin.

The film grain layer is a tiny square of random noise, tiled over the canvas at a random offset every frame with very low opacity. It's nearly invisible — but turn it off and the gradient suddenly looks cheap and "banded". Grain is the difference between a screensaver and a cinematic background.