# ColorLookup

> Per-channel colour curves.

| Node | ColorLookup |
|---|---|
| Menu | Color › ColorLookup |
| **Names in each format** | |
| .oink comp (JSON) | `"type": "OC_N_colorlookup"` |
| .nk script | `ColorLookup` ([how .nk import works](/docs/nuke-users/nk-import)) |
| Python | `nuke.createNode("ColorLookup")` |
| Assistant (MCP) | `create_node(type="ColorLookup")` |
| Tab search | `colorlookup`, or its initials `cl` |

![ColorLookup properties](/shots/nodes/colorlookup@2x.webp)

## Inputs and outputs

| Port | Name | Type |
|---|---|---|
| input 0 | Image | image |
| input 1 | mask | image |
| output 0 | Image | image |

## Knobs

Panel tab **ColorLookup**, in panel order.

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `channels` | channels | menu | `rgba` | rgba, rgb, alpha, all, none |  | Layer the op applies to: rgb, rgba, alpha, all, none, <layer> or <layer>.<ch> |
| `use_precomputed` | use precomputed table | bool | `true` |  | `use_precomputed` |  |
| `range` | range | float | `1` | 0 to 10 | `range` |  |
| `lut` | lut | curves | `{master {} red {} green {} blue {} alpha {}}` |  |  |  |
| `source` | source | colour ×3 | `0, 0, 0` | 0 to 1 | `source` |  |
| `target` | target | colour ×3 | `0, 0, 0` | 0 to 1 | `target` |  |
| `setRGB` | Set RGB | button (panel only) |  |  |  |  |
| `setRGBA` | Set RGBA | button (panel only) |  |  |  |  |
| `setA` | Set A | button (panel only) |  |  |  |  |
| `mask_channel` | mask | menu | `none` | none, rgba.alpha, rgba.red, rgba.green, rgba.blue |  | Mask channel, e.g. rgba.alpha (none = no mask) |
| `inject` | inject | bool | `false` |  |  | Copy the mask into mask.a for nodes downstream |
| `invert_mask` | invert | bool | `false` |  | `invert_mask` |  |
| `fringe` | fringe | bool | `false` |  |  | Only apply the effect at the edges of the mask |
| `unpremult` | (un)premult by | menu | `none` | none, rgba.alpha |  |  |
| `invert_unpremult` | invert | bool | `false` |  |  | (Un)premultiply by 1 - alpha |
| `mix` | mix | float | `1` | 0 to 1 | `mix` |  |

### Other knobs (Python, .nk and the assistant; not on the panel)

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `gl_color` | Viewer Controls Color | float ×3 | `0, 0, 0` | 0 to 1 |  |  |
| `postage_stamp_frame` | Static Frame | int | `1` | -2147483648 to 2147483647 |  |  |
| `lifetimeStart` | Lifetime Start | int | `0` | -2147483648 to 2147483647 |  |  |
| `lifetimeEnd` | Lifetime End | int | `100` | -2147483648 to 2147483647 |  |  |
| `useLifetime` | Use Lifetime | boolean | `false` |  |  |  |
| `cached` | Cached | boolean | `false` |  |  |  |
| `bookmark` | Bookmark | boolean | `false` |  |  |  |
| `dope_sheet` | Dope Sheet | boolean | `false` |  |  |  |
| `clone_group` | Clone Group | string |  |  |  |  |
| `link_source` | Link Source | string |  |  |  |  |
| `link_overrides` | Link Overrides | string |  |  |  |  |
| `split_views` | Split Views | string |  |  |  |  |


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Sources: opencomp_core/nodes/color/lookup_nodes.py, opencomp_electron/src/components/properties/knobSchema.ts, opencomp_core/nk/mapping.py