> ## Documentation Index
> Fetch the complete documentation index at: https://comfytv.org/llms.txt
> Use this file to discover all available pages before exploring further.
# Select0r
> A color-region keyer that carves a matte out of a chosen color space with tunable shape and edge falloff.
## What this node does
Select0r pulls a matte by selecting a region of color around a key color inside a chosen color space. Rather than a single threshold, it defines a 3D selection volume — a box, ellipsoid, or octahedron — sized independently on each axis, with a controllable edge falloff. This makes it good for isolating a specific color range (a screen, a shirt, a sky) with a soft, shapeable boundary.
Input and output are `COMFYTV_VIDEO`. It runs as a live fx-preview filter (emits an fx spec and passes through), so results preview without a full render.
## When to use it
* You want to key on a color range, not just a flat screen, and need control over the region shape.
* A simple chroma key's spherical tolerance is too crude — you need per-axis sizing.
* You're isolating a color for a secondary grade or selective effect.
## Parameters
### key\_color
The center color of the selection. Hex, default `#00FF00`.
### space
The color space the selection lives in: `rgb` (default), `abi`, or `hci`. Different spaces separate color and brightness differently — switch if the key is easier to isolate in one of them.
### shape
The geometry of the selection volume: `box`, `ellipsoid` (default), or `octahedron`. Ellipsoid gives smooth falloff; box is hard-cornered; octahedron is in between.
### edge
The edge falloff profile: `hard`, `fat`, `normal` (default), `skiny`, or `slope`. Controls how the matte transitions at the region boundary — from crisp to feathered.
### delta\_1 / delta\_2 / delta\_3
The size of the selection region along each of the three axes of the chosen color space. Each ranges `0.001`–`2.0` (step `0.005`), default `0.2`. Larger deltas select a wider range of colors on that axis.
### slope
Softness of the edge transition. Range `0.001`–`1.0` (step `0.005`), default `0.2`. Higher values feather the matte boundary more.
### invert
When on, inverts the matte (select everything except the color region). Default off.
### output
`matte` (default) returns a grayscale matte; `image` returns the footage carrying the selection.
## Outputs
| Output | Type | Meaning |
| --------- | --------------- | ----------------------------------------------------------- |
| **video** | `COMFYTV_VIDEO` | The selection matte, or the image when `output` is `image`. |
## Tips
* Start with `ellipsoid` + `normal` edge, then grow `delta_1/2/3` until the color is fully covered without spilling into neighbors.
* Try `abi` or `hci` space when RGB can't cleanly separate your target color from similar ones.
* Turn on `invert` when it's easier to describe what you want to keep than what you want to remove.
* To interoperate with native ComfyUI nodes, insert a **Bridge**. See [bridges.md](https://github.com/jtydhr88/ComfyTV/blob/main/docs/bridges.md).
## Related nodes
* **Keyer** / **PIK Keyer** / **Chroma Key** — other keyers producing mattes.
* **Matte Morphology** — clean the Select0r matte.
* **Key Mix** — composite through the matte.
* **Matte Monitor** — inspect matte quality.