ColorBox by Lyft Design

I don’t really understand what this colour tool is doing or what it’s for, but I like it.

The HSB Color System: A Practicioner’s Primer – Learn UI Design

A nice clear explanation of specifying colour using HSB (not to be confused with HSL).

Out of the (Drop)Shadows | Scott Jensen Design

Can an opinionated flat design still have depth and truly be free of drop shadows?

Scott proposes a technique that mimics atmospheric perspective—y’know, when things in the distance look hazier than things in the foreground.

The fact is, we are surrounded by a world that is full of depth, and very little of it is defined by shadow. If we are going to replace drop shadows in our visual UI metaphors, we should look at other options that create depth in the world around us.