🔧 Image Apply LUT

If you do color grading in video or photo tools, you know LUTs - those .cube files that stamp a whole look onto an image in one shot. Image Apply LUT brings that straight into ComfyUI: drop a .cube file into the pack's LUT folder, pick it from the dropdown, and your generation gets that grade. It's the quickest way to give AI images a consistent, film-like color treatment.

Why you'd reach for it

Prompting your way to a precise color look is unreliable, and hand-tuning curves per image doesn't scale. A LUT (lookup table) is a fixed color transform - teal-and-orange, a film emulation, a cool cinematic wash - that applies the exact same mapping every time. If you've got a house style, or you want a batch of outputs to share one grade, a LUT nails it in a single deterministic step. This node is the finishing-pass color grader: run it near the end of your workflow, after the image is otherwise done, to lock in the look.

How it works

It applies a 3D color LUT from a .cube file to your image. lut_file is a dropdown of the LUT files the node found in its LUTs directory. strength blends the graded result with the original (1.0 = full LUT, lower = a subtler touch), so you can dial the intensity instead of getting all-or-nothing. gamma_correction and clip_values are correctness toggles: gamma correction keeps the transform accurate across color spaces, and clipping keeps output values in a valid range. Leave both on unless you have a specific reason not to.

Inputs and outputs

Input is image; output is IMAGE (the graded result). The controls: lut_file (which LUT - the important one), strength (how strongly to apply it), and the two booleans gamma_correction and clip_values. In everyday use you're really just picking a LUT and nudging strength.

Installing it

Part of ComfyUI Essentials by cubiq (Matteo Spinelli, the IPAdapter node author). ComfyUI Manager: search ComfyUI Essentials, install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/cubiq/ComfyUI_essentials

then restart. It's 🔧 Image Apply LUT under essentials/image processing, class ImageApplyLUT+. Maintenance-only pack since April 2025.

Common issues

Here's the one that trips up almost everyone: the node ships with no LUTs. If the only thing in the lut_file dropdown is a placeholder like put_luts_files_here.txt, that's the node telling you the LUT folder is empty. You have to add your own .cube files to the pack's luts directory (inside ComfyUI/custom_nodes/ComfyUI_essentials/), then restart ComfyUI so the dropdown re-scans - new files won't appear until you reload. Free .cube LUTs are easy to find online. After that: if the grade looks crushed or washed, try toggling gamma_correction, since a LUT authored for a different color space can look wrong without it, and pull strength down if the look is too heavy.