LayerColor: LAB

LAB Color Adjust is the color-correction node for when HSV is too blunt. It works in LAB space, which splits an image into lightness and two color axes that are completely independent of that lightness - so you can shift color without changing brightness, or change brightness without muddying color. If you've ever brightened an image and watched the colors go flat and weird, or corrected a color cast and lost contrast, this is the tool that avoids both. It's the more surgical sibling of the pack's HSV node.

The mechanism: convert to CIELAB, offset the channels, convert back. What makes LAB special is that the three channels don't interfere. L is pure lightness. A is the green-to-red axis. B is the blue-to-yellow axis. Because color and luminance are decoupled, a white-balance fix on the A/B axes leaves your tones exactly where they were, which is the whole reason colorists reach for LAB.

Three controls, each −255 to 255 with 0 as neutral:

• L - lightness. Positive brightens, negative darkens, and unlike an HSV value shift it moves brightness without touching the hue or vividness.
• A - the green↔red axis. Push positive toward red/magenta, negative toward green. This is half of a white-balance correction.
• B - the blue↔yellow axis. Positive toward yellow (warmer), negative toward blue (cooler). The other half of white balance, and the fastest way to warm up or cool down an image cleanly.

One output, image, the corrected picture, ready to sit anywhere in the chain.

Where LAB earns its keep over HSV: correcting a color cast (a render that's too blue - nudge B positive and it warms without dulling), doing white balance properly (the A/B pair is white balance), or adjusting brightness on a graded image without collapsing the color you worked to get. The classic "LAB move" is a small A/B tweak to neutralize a cast while L stays put, which keeps every tonal relationship intact.

Manage expectations the same way as HSV: this is a global offset, applied to every pixel equally. It's for overall correction and grading, not for changing one object's color - for that, mask the region and apply the adjustment through it. And LAB's sensitivity cuts both ways: because the axes are perceptual, small values do real work, so start gentle. A/B shifts of a few dozen units are often plenty; slamming them to the extremes gives you the same surreal recolors as a big hue swing.

Install rides with the ComfyUI Layer Style pack. ComfyUI Manager: search "ComfyUI Layer Style," install, restart. Manual: cd ComfyUI/custom_nodes && git clone https://github.com/chflame163/ComfyUI_LayerStyle, then pip install -r requirements.txt in the ComfyUI environment and restart. No model download.

Troubleshooting is the pack-level story: Layer Style is large and dependency-heavy, and its most common failure is the entire pack showing "import failed" in the Manager (a transformers version conflict, usually), which drops every node - LAB included - from your menu at once. If it's missing, that's the reason: reinstall the pack, use the Manager's "Try Fix," and reinstall the requirements into ComfyUI's real Python environment if it doesn't clear.