> ## Documentation Index
> Fetch the complete documentation index at: /llms.txt
> Use this file to discover all available pages before exploring further.

# Color grading implementation

> Persist, automate, animate, and spatially isolate media color grading.

Use this reference when browser editor controls are not enough: you need to write a
grade into HTML, apply it from automation, animate a supported property, or
limit an effect to a composited region. For visual correction and everyday
browser editor use, start with [Color grading](/guides/media-effects.md#fix-and-grade-the-color).

## Persist a grade

The browser editor and the CLI store the resolved grade in `data-color-grading`:

```html
<video
  id="interview"
  src="./assets/interview.mp4"
  data-color-grading='{"preset":"skin-soft","intensity":0.7}'
></video>
```

Apply the same validated payload from the CLI:

```bash
npx hyperframes media-treatment \
  --selector '#interview' \
  --grading '{"preset":"skin-soft","intensity":0.7}' \
  --apply
```

Add `--dry-run --json` to inspect the change without writing it. Use `--clear`
to remove the treatment.

## Grade a whole lane

A camera cut into hundreds of clips takes one grade, set once. Put the grade
on an `<hf-color-group>` and point each clip at it with `data-color-group`:

```html
<hf-color-group
  id="tamer-cam"
  data-label="Tamer"
  data-color-grading='{"preset":"skin-soft","intensity":0.7}'
></hf-color-group>

<video id="tamer-01" data-color-group="tamer-cam" src="./assets/tamer.mp4" …></video>
<video id="tamer-02" data-color-group="tamer-cam" src="./assets/tamer.mp4" …></video>
<video
  id="tamer-03"
  data-color-group="tamer-cam"
  data-color-grading='{"adjust":{"exposure":0.3}}'
  src="./assets/tamer.mp4"
  …
></video>
```

* `data-color-grading` on the group takes the same JSON as on a clip. Editing it
  regrades every member, in preview and in render.
* `data-color-group` goes on the `<video>`, `<img>` or `<canvas>`. Membership is
  held by the member, so a deleted clip simply leaves the group.
* **A clip's own `data-color-grading` wins.** It replaces the group's grade for
  that clip, so `tamer-03` above gets only its exposure lift, not skin-soft.
* `data-color-group=""` is no group, and a group id with no `<hf-color-group>`
  element leaves the clip ungraded. Removing the element, or its
  `data-color-grading`, ungrades its members.
* Groups do not nest. Group ids share the element-id namespace.
* The element is inert: the runtime injects
  `hf-color-group{display:contents!important}`. Close it with
  `</hf-color-group>`, since HTML ignores `/>` on a custom element.

## Animate a supported property

Nine grading properties expose CSS custom properties that a paused timeline
can tween directly:

```text
--hf-color-grading-ascii
--hf-color-grading-bloom
--hf-color-grading-blur
--hf-color-grading-dither
--hf-color-grading-exposure
--hf-color-grading-intensity
--hf-color-grading-kuwahara
--hf-color-grading-pixelate
--hf-color-grading-lut-intensity
```

Once set, a property overrides the payload's value for that control, whether it
comes from the element's inline style, a stylesheet or a parent. Set it only on
media you animate, starting at the value the tween begins from; leave it unset
for a static grade. Then animate it on the registered timeline:

```js
tl.to(
  "#plate",
  {
    "--hf-color-grading-pixelate": 0.5,
    duration: 3,
    ease: "power2.inOut",
  },
  0.3,
);
```

`--hf-color-grading-intensity` scales the primary correction, wheels, curves,
selections, and LUT. It is not a master control for detail and effect families
such as grain, halftone, bloom, tape, or CRT. Animate the specific exposed
property and verify that it moves before relying on it.

## Limit a grade to part of the frame

Grading selects pixels by value, not position. To treat one region, isolate it
as its own media layer:

| Result | Layer stack |
| - | - |
| Grade the subject only | Clean original plate, then a graded subject cutout |
| Grade the background only | Graded original plate, then a clean subject cutout |
| Grade one region of the subject | Clean cutout, then a second graded cutout clipped to the region |

```html
<video
  src="media/room.mp4"
  muted
  data-start="0"
  data-duration="4"
  data-track-index="2"
></video>
<video
  src="media/subject.webm"
  muted
  data-start="0"
  data-duration="4"
  data-track-index="3"
></video>
<video
  src="media/subject.webm"
  muted
  data-start="0"
  data-duration="4"
  data-track-index="4"
  style="clip-path: ellipse(9.8% 15.5% at 50.7% 14.5%)"
  data-color-grading='{"intensity":1,"effects":{"pixelate":0.5}}'
></video>
```

Use the original clip as the background plate. A subject-removed plate leaves a
hole and can create a dark edge beneath a feathered cutout. A fixed `clip-path`
works only when the subject barely moves; real movement needs a tracked matte
produced outside HyperFrames.