fx_color kernels mirror the CPU effects operation for operation: one per-pixel
pass for the point effects, Lumetri with its Sharpen luminance blur, and Key
Light's matte pipeline (pre-blur, clip, rollback, despot, shrink/grow, softness,
edge band) as plane passes. CPU fallback: Key Light with Inside/Outside masks or
Hard Colour after Screen Softness, Colorama with Interpolate Palette off.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>