- Pick one lightness value (L) for your main colours, for example 0.72.
- Pick one chroma value (C), for example 0.14.
- Change only the hue (H) to get your set: say 30, 150 and 250.
- For tints and shades, change only L and keep C and H fixed.
In CSS that's oklch(0.72 0.14 250). Because OKLCH is perceptual, the colours look equally bright, which plain HSL can't promise.
Sources
Further reading from CG Channel. Read the original for full detail.
