# When Generated Clips Arrive in HDR: Kling 4.0 and the Colour Pipeline

- Published: 11 October 2026
- Updated: 11 October 2026
- Author: RenderBob team
- Category: Technical
- Canonical: https://renderbob.ai/blog/generated-clips-in-hdr-kling-4-colour-pipeline

Kling 4.0 Flash is reported to offer 10-bit HDR, and Runway Ruby converts SDR to HDR. A mixed timeline needs a colour decision before the first cut.

For two years, generated video has been an SDR affair: eight-bit, Rec.709-ish, and easy to drop beside camera footage. That is starting to change. Kuaishou says Kling 4.0 will launch officially in October, and a limited early-access group has had Kling 4.0 Flash since 28 September. As announced, it produces 3 to 30 second clips at up to 4K with stereo audio and 10-bit HDR output. Treat that as a claim until the release is public. Elsewhere, Luma's Ray3.2 is positioned for HDR finishing, and Runway's Ruby, added in August, converts SDR video to HDR, including output from other models.

## Why this matters to editors

A timeline that mixes SDR camera footage, SDR generated clips, and HDR generated clips needs a colour-space decision before the first cut. Colour guidance from several sources makes the same point: a mismatch between timeline, monitoring, export, and platform expectations is one of the most common reasons footage looks washed out after upload. Rec.709 is generally the safe choice unless the whole workflow was designed for HDR from the start.

## Decide the delivery space first

If the final is SDR, treat HDR generated clips as sources to tone-map, not as a reason to switch the timeline.

## Tag every clip on import

Tag colour space and transfer function on import, and confirm the editor reads the metadata instead of guessing.

## Grade after normalising

Colour tools tend to misjudge material that has not been brought into the working space.

## Compare models side by side

Generated clips from different models often differ in contrast and saturation even at the same nominal settings.

## Test the export on the platform

Test the export on the target platform before the deadline.

## Converted HDR and native HDR

A converter has to invent highlight detail that was never recorded. That can look convincing, or it can look synthetic. Native HDR generation raises a different question: how the model was trained and evaluated for HDR. Neither answer is well documented for editors yet.

## A short colour test for hybrid timelines

Many projects will mix real footage, graded generations, and archive. The cheapest insurance is a short colour test: one real clip, one generated SDR clip, and one generated HDR clip, graded and exported together. If they hold together there, they will probably hold together in the cut.

## What to watch

Delivery specs. If broadcasters and platforms start asking for HDR masters of AI-assisted work, colour handling becomes part of choosing a model, not only a finishing step.