Comment by electrosaur

I'm building Reveal, an open-source color separation engine for screen printing. It takes a full-color image and reduces it to 3-10 spot colors. This is not for CMYK 4-color process or simulated process ('halftones' using opaque colors).

The core is pure JavaScript with zero dependencies. It works in Lab color space (not RGB) using Wu quantization, CIE perceptual distance metrics, and a DNA fingerprinting system that matches each image to one of 20+ built-in archetypes (Golden Hour, Dark Portrait, Fine Art Scan, etc.).

There's a browser-based web UI that just needs Node.js — drop an image, get 4 different possible separations side by side, export as layered OpenRaster (for GIMP/Krita), or flat PNG, or layered PSD (for Photoshop). There's also a CLI and Photoshop plugin.

Apache 2.0: https://github.com/electrosaur-labs/reveal

Some of my screen prints: https://www.electrosaur.org