Contrast is a macOS app for designers and developers that provides quick access to WCAG color contrast ratios.
Skala Color is a compact and feature-rich macOS color picker that works with a huge variety of formats, covering everything you’re likely to need for web, iOS, Android, and macOS development — Hex, CSS RGBA, CSS HSLA, UIColor, NSColor and more.
Chameleon is a macOS app that gives quick access to changing the interface, accent and highlight colors from the menu bar. It has a very simple interface, if you've used the System Preferences panel to make any changes then it should look really familiar.
.colors() allows you to paste any code you like to quickly figure out the color palette that's hidden in it. Whether it be CSS, JS, or whatever else. As long as there's a CSS-compatible color in there, the tool will gather it for you.
You can even sort the colors you found and get a sorted array! ✨
Very handy for quickly dealing with colors!
Data Color Picker is a UI tool for easy to read data visualizations