Primitive Color CMYK (MD)

CMYK is the color space of ink, not screens - cyan, magenta, yellow and black percentages that describe what a printer lays down. AI work is sRGB through and through, so you'll rarely need this node. But if you're handed a brand palette in CMYK percentages (a shocking number of real-world design specs are), or you just want to see what a print-color looks like on screen, mdPrimitiveColorCMYK converts those four values into a packed RGB integer and a #RRGGBB hex string.

How it works

Each of the four inputs is a percentage from 0 to 100. The node normalizes them to 0–1 and applies the classic naive CMYK→RGB formula:

• R = (1 − Cyan) × (1 − Key)
• G = (1 − Magenta) × (1 − Key)
• B = (1 − Yellow) × (1 − Key)

Then it clamps and packs as (R << 16) | (G << 8) | B, same as the other primitive color nodes here. Note the "Key" input is black - that's the K in CMYK. At all zeros you get white; raise everything toward 100 and you sink toward black.

The inputs and outputs

• Cyan / Magenta / Yellow / Key - 0 to 100%, defaults 0.
• Output int - packed color integer (0–16777215).
• Output HEX - hex string.

Install

Part of the MdColorMod pack, no dependencies, no models:

cd ComfyUI/custom_nodes
git clone https://github.com/MdONeilsl/ComfyUI-MdColorMod

Restart ComfyUI, or install via ComfyUI Manager by searching "MdColorMod".

Where people get burned

This conversion is the simple, naive CMYK→RGB - the one that ignores ICC profiles and black-generation curves. Real print pipelines do far more, so treat the result as "approximately this color on screen," not a proof. If the color looks off from what you expect, that's inherent to the naive formula, not the node misbehaving. And the usual primitive-color reminder: the int output is a number for color-INT inputs, not a pixel.