Color Stylizer

You've seen the effect a hundred times - a black-and-white photo with just the red rose or the yellow umbrella left in full color. Color Stylizer does that "color pop" trick to any image: pick a color to keep, and it desaturates everything that isn't close enough to it.

What it is and why you'd use it

This is a selective-desaturation node, part of the same October 2023 batch that added Query Local LLM and the SDXL resolution nodes to the CrasH Utils pack. It's a straightforward stylistic finisher - good for pulling focus onto a single colored subject the model generated, product-shot style highlighting, or chasing that Sin City-esque look where one element stays vivid against a grey world.

How it works

It measures how far each pixel's color is from a target RGB value you set, keeps color on pixels within range, and desaturates the rest. Two knobs control the shape of that decision: how wide the "counts as a match" range is, and how aggressively non-matching pixels get greyed out.

Inputs and outputs that matter

• target_r, target_g, target_b - the color to preserve, as three 0–255 sliders instead of one hex swatch. Default is 255/255/255 - pure white - which is almost never what you actually want, so the first thing to do is set these to your subject's actual color before judging the effect.
• falloff - 0–100, default 30. How much a pixel's color can drift from your target and still count as a "keep." Too low and only near-exact matches survive, leaving patchy, broken-looking results; too high and almost everything stays colored, which defeats the point.
• gain - 0–10 in steps of 0.5, default 1.5. Controls how hard the non-matching areas get pushed toward grey - values above 1 push past a flat, even desaturation into something closer to overdriven/crushed.

Output is a single image.

Installing it

ComfyUI Manager: search "CrasH Utils". Manual:

cd ComfyUI/custom_nodes/
git clone https://github.com/chrish-slingshot/CrasHUtils.git

Restart ComfyUI. No dependencies.

Common issues

"I ran it and basically nothing happened." Almost always the default-target trap: target_r/g/b starts at white, and most photos don't have much pure white in them, so the effect looks like a no-op. Change the target to the actual color of the thing you want to keep first.

Result looks patchy or broken, like the color is only surviving in weird spots. falloff is too low for the amount of natural variation in your subject's color (lighting, shading, and compression all shift a "red" object's actual pixel values around). Raise it gradually until the whole subject holds together.

Barely any desaturation at all, or way too much stays colored. Same knob, opposite direction - falloff set too high means background elements that are only loosely similar to your target color are getting swept in as "matches" too. Bring it down.

Grey areas look harsh or crushed instead of soft. That's gain pushed too high. Values near the top of its 0–10 range are meant for a stronger, more stylized crush; drop it back toward 1.0–1.5 for a gentler classic desaturation.

Picking the exact target color by eye is annoying. There's no built-in eyedropper on this node - sample the color from a reference image in an external tool (or another ComfyUI color-picker node if you have one installed) and type the RGB values in manually.