Shuffle Custom Colors

Materials are full of regions you can describe by color before you can describe by geometry. The rust spots on a metal plate, the grime in the crevices, the burned patch on the wood - Shuffle Custom Colors turns "the pixels that are this hex color" into a proper mask. It's a color-picker masquerading as a node, and for texturing it's one of the most useful mask sources in the pack.

How it works

The colors input is an autogrowing list of hex color strings - you add a slot, type #8B4513, add another, done. The node parses them, then measures how close every pixel is to your chosen color. tolerance (0 to 1, default 0.2) decides how far from the target a pixel can be and still count; feather (default 0.1) softens the mask edges so you don't get hard pixel-crisp boundaries. mode picks the distance metric: rgb is raw channel distance, hsv is distance in hue/saturation/value space (better when lighting shifts the brightness but not the hue), and luminance compares brightness only - perfect for "all the dark crevices" masks where the actual color is irrelevant.

The trick parameter is channel_index. You can have up to 50 colors defined, and this integer picks which one builds the mask - 0 for the first, 1 for the second, and so on. It's a connectable input, so you can drive it from an LLM or a logic node to flip between color-based masks in one workflow instead of maintaining a stack of separate mask nodes.

The output

A single MASK, ready to wire into a compositor, a blend, a detail-mixer, or an inpaint crop. This is the node you reach for when you want the mask to follow the material - mask the rust so you can roughen it, mask the metal so you can brighten it - without any segmentation model in the pipeline.

Installing it

Part of amtarr/ComfyUI-TextureAlchemy ("Texture Alchemy" in ComfyUI Manager). Or:

cd ComfyUI/custom_nodes
git clone https://github.com/amtarr/ComfyUI-TextureAlchemy

Restart, then right-click → Add Node → Texture Alchemist → Masks. Pure PyTorch under the hood, no extra dependencies, no models.

Where people get burned

Tolerance is the trap. Set it too low and you get a dotted mask as anti-aliased edges drop out; too high and the mask bleeds into neighboring colors - the classic failure is selecting rust and getting half the metal too, because weathered metal is a gradient between the two. If your material has color gradients, pick the middle of the range you care about and let tolerance + feather cover the rest. And luminance mode will ignore hue entirely, so don't use it when red and blue objects both sit in your image and you only want one.