FR: Browser/WebSocket: color6 support

[Westworld]

Feature request to support color6 (64 colors) for WebSocket/Browser output
Serum based colorisation uses 64 colors in a color6 encoding. Currently they are converted to 24bit RGB, producing so many web packets that the browser got lost, way behind in display, wrong order, even get stuck.

A solution would be to support color6 directly, which would reduce traffic drastically.
This would also require to support color rotation.
Still I noticed that often package (frames) arrives in wrong order, so a filter to skip older frames would help