What are OKLCH colors?

Does anyone know how this is different to the Munsell color space, which is also perceptually uniform?

Edit: I would imagine that the only way to definine a perceptually uniform color space is by tons of user testing. This is how Munsell developed his color space… specifically presenting test subjects with pairs of identical and near-identical color swatches and asking if they could tell the difference.

In this way, pairwise comparisom of similararity became the bedrock of color perception science.

My understanding is that it's the same with higher resolution.

Oklch is open source and part of the web standard, Munsell colors probably needs a licence to be used ?

The Munsell color system isn't really intended for displays, rather it's a collection of pigments, similar to Pantone. The transforms can get a bit weird (for example, since the swatches are discrete, there's no defined way to get intermediate colors). Munsell's ideas, particularly the axes of hue, value, and chroma, have absolutely influenced modern color spaces and are very much on display in the OKLCH space.