Request: Integrate HCT Color Space Library for Accessibility Contrast Checks

**Description:**
I’m not sure if this issue will be reviewed, but I’d like to leave it here for record-keeping and future consideration.

When performing accessibility color contrast checks within the Iris project, I recommend adopting a modern perceptual color space — specifically, the **HCT (Hue, Chroma, Tone)** color space. It provides far more reliable and human-perceptual contrast accuracy compared to traditional sRGB or HSL comparisons.

**Reason:**

* HCT (as used in Material Design 3) better reflects human color perception.
* It ensures more accessible and perceptually balanced color contrast evaluations.
* It simplifies handling light/dark modes and dynamic color schemes.

**Reference:**

* [[Material Design HCT Overview](https://m3.material.io/styles/color/the-color-system/key-colors-tones)](https://m3.material.io/styles/color/the-color-system/key-colors-tones)

**Suggestion:**
Consider integrating an existing open-source HCT implementation, such as [[material-foundation/material-color-utilities](https://github.com/material-foundation/material-color-utilities)](https://github.com/material-foundation/material-color-utilities), for more precise and perceptually correct contrast calculations.

Thank you for your consideration!

https://github.com/WordPress/gutenberg/issues/69797

Start by locating Iris’s existing accessibility contrast-checking entry point and reviewing the linked Gutenberg issue and Material Design HCT reference. Before implementation, a maintainer should define the integration scope, accepted library, compatibility requirements, and validation criteria; done should mean those criteria are met with an agreed test or review path.

Written by the indexing model from the issue text.