The way CSS handles color is changing forever. New displays support wider gamuts, "colors you RGB and HSL people wouldn't even imagine". With OKLCH, color finally becomes human again: intuitive, readable, predictable. The lightness you set in code is the lightness your eye perceives, and with calc() you can generate entire dynamic palettes in a simple, clear way. Once you get it, you won't want to go back.
Talk in Italian.