Saturation Mask

Selects pixels by how vivid they are, not by where they are. Use it to grab only the loud colours, only the dull ones, or everything in between.

In ComfyUI	Add Node → ComfyUI-JH-PixelPro → color → Saturation Mask Builder
Good for	Taming oversaturated clothing or backgrounds, boosting only dull areas, protecting already-vivid colours from a grade

When to use it

Saturation is how strong a colour is: a neon sign is highly saturated, a grey wall has almost none. A saturation mask works like a luminosity mask (a selection made from brightness), but it follows colour strength instead.

Typical uses:

• Pull down only the over-saturated reds in a dress without touching skin.
• Lift only the flat, washed-out areas.
• Feed the mask into any node that accepts a MASK, such as LUT Import, so a grade only lands where you want it.

The value is measured as HLS saturation (hue, lightness, saturation), the same idea as the saturation slider in most editors.

Quick start

1. Connect Load Image → Saturation Mask Builder.
2. Leave sat_min at 0.30 and sat_max at 1.00 to select the vivid part of the picture.
3. Connect the mask output to Mask Preview to see the selection, or to the mask input of another node.
4. Move sat_min up to narrow the selection to only the strongest colours.

Settings

Setting	Default	What it does	Tip
sat_min	0.30	Lowest saturation that is included (0 to 1).	Raise it to ignore dull areas.
sat_max	1.00	Highest saturation that is included (0 to 1). Must be larger than sat_min.	Lower it to leave the most vivid colours out.
feather	0.10	Softness of the edges around both limits (0 to 1).	0 gives a hard on/off mask; 0.05 to 0.15 avoids visible steps.

Output: mask — a MASK with values from 0 (not selected) to 1 (fully selected), one per image in the batch.

Tips from retouching

• Keep some feather. A hard threshold on saturation produces blotchy, noisy selections on skin and fabric.
• To protect already-vivid colours, select a low range (for example sat_min 0, sat_max 0.4) and apply your grade through that mask.
• Skin sits in a middle saturation band. If a grade is affecting skin, combine this mask with a hue selection using Hue/Saturation per Range.
• Clean up speckles with Mask Cleanup before using the mask on a final export.

Under the hood

The image is converted to HLS and the saturation channel is compared with the range. With feather at 0 the result is a binary mask. Otherwise each limit gets a smoothstep ramp of width feather (the lower ramp ends at sat_min, the upper ramp starts at sat_max), and the two are multiplied. sat_max must be strictly greater than sat_min, otherwise the node raises an error. The same function drives the saturation step inside some Look Select presets.

Related nodes

• Hue/Saturation per Range — adjust colour inside a hue band.
• Luminosity Masking — the brightness-based equivalent.
• Mask Combine — multiply or add this mask with other selections.
• Look Select — uses saturation masks inside some looks.

Example workflow

Selective color example workflow. It builds a Saturation Mask from the portrait, shows it as a heatmap, and uses Hue/Saturation per Range on one colour band. Copy workflows/sample_portrait.jpg into ComfyUI/input/. It uses only core ComfyUI nodes and this pack.