Edge Glow

Edges light up where colors change sharply.

Color & Effects · a single painted seed plus one Phlux rule, simulated live · 96×96 grid

The rule that makes it move

This is the whole thing. Phluxel runs it on every cell, every step — the animation is what happens when you repeat it.

R = {STDDEV,(-1:1,-1:1).R} * 8; G = {STDDEV,(-1:1,-1:1).G} * 8; B = {STDDEV,(-1:1,-1:1).B} * 8

Paste it into the Rule Editor, or pick Edge Glow from the template list and skip the typing.

Make it yourself

1. Open Phluxel and start a new field, or click Edge Glow in the starter gallery to get this exact setup.
2. Leave Wrap edges off — this one is meant to have real borders.
3. Press play. Change colours or numbers while it runs; you never have to stop and restart.
4. Export a seamless loop as GIF, APNG, MP4, a PNG sequence, or a sprite sheet.