Regional Seed Explorer By Color Mask (Inspire)

You've got a generation you mostly love, but one area is off - the face is fine, the pose is great, but the background is boring, or vice versa. Re-rolling the seed changes everything, and you lose the parts you wanted to keep. Regional Seed Explorer By Color Mask solves exactly that: it lets you introduce seed variation into a masked region only, freezing the rest of the noise so the good parts stay put.

This is the "color mask" variant - you define the region by a color in a reference image rather than by supplying a mask directly. Handy when you're already using color-coded region maps (a common pattern in Inspire's regional workflows), because the same map that assigns prompts can pick out the area to explore.

How it works

It works on the noise, not the finished image. You feed it an existing NOISE_IMAGE (from Inspire's RandomNoise node), and within the masked region it blends in variation seeds you list in a seed prompt. The pack's Seed Explorer syntax is comma-separated seed:strength entries - the first seed is the base, and each additional one nudges the noise a little toward that seed at the given strength. Outside the mask, the original noise is left alone. Feed the resulting noise into a sampler that accepts a noise input and you get the same image with only the masked area rerolled.

variation_method decides how the seeds blend: linear is a straight interpolation, slerp is spherical (the technique borrowed from BlenderNeko's noise code) and usually the better-behaved choice for noise. noise_mode picks GPU (A1111-style) or CPU noise generation.

The inputs and outputs

The ones that matter:

• color_mask (IMAGE) and mask_color (STRING, default #FFFFFF) - the region map and the hex color that marks the area to explore.
• noise (NOISE_IMAGE) - the base noise you're modifying.
• seed_prompt (multiline STRING) - your seed:strength list; this is the actual exploration control.
• additional_seed / additional_strength with enable_additional - a convenience for appending one more seed on top without editing the prompt.

Outputs are the modified NOISE_IMAGE (into your sampler's noise input) and the MASK it resolved from the color map. variation_method (linear/slerp) is an optional input.

How to install it

ComfyUI Manager: Install Custom Nodes → search ComfyUI Inspire Pack → install → restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/ltdrdata/ComfyUI-Inspire-Pack

Then restart. It's Dr.Lt.Data's pack, so it installs cleanly with no model downloads for this node.

Common issues

The biggest hurdle is that this manipulates noise, which means it only works with a sampler setup that takes an injected NOISE_IMAGE - a plain KSampler generates its own noise internally and ignores yours. You'll typically pair it with Inspire's RandomNoise plus a sampler wired to accept the noise. Second, the mask_color has to actually match a color present in color_mask - an exact hex mismatch selects an empty region and you'll see no variation at all. And keep strengths modest; high seed:strength values or a strength near 1.0 push the region far enough that it stops looking like a variation and starts looking like a different image.