L is for lightness (0-100%), C is for chroma (0-0.5), H is for hue (0-360deg).
Lightness dictates how white or black a color is, chroma dictates how saturated it is, and hue is which angle on the color wheel it occupies. Varying these one at a time lets you intuitively pick colors that are close to one another in the space of human perception. And CIE Lab colors are especially nice because they cover more than the sRGB gamut that we're all used to defining with HSL or RGB, so you can really make the most of your fancy wide color gamut monitor.
Unfortunately in the CSS implementation of oklab Chroma takes priority over Lightness, so if you have high Chroma and Lightness at 100% that results in a color outside the RGB gamut, it will not give you white, but the lightest color with that Chroma. To me this is quite counterintuitive.
> L is for lightness (0-100%), C is for chroma (0-0.5), H is for hue (0-360deg).
My programmer brain immediately jumped away in disgust.
I'm sure there's many good reasons for choosing those, but it seems to me it could have easily have been done with 3 percentages (0-100% for the 3 numbers). Way easier to work with programmatically.
Lightness dictates how white or black a color is, chroma dictates how saturated it is, and hue is which angle on the color wheel it occupies. Varying these one at a time lets you intuitively pick colors that are close to one another in the space of human perception. And CIE Lab colors are especially nice because they cover more than the sRGB gamut that we're all used to defining with HSL or RGB, so you can really make the most of your fancy wide color gamut monitor.