Colour
Palettes, pickers and conversions.
About these tools
Colour work on the web is mostly translation. A brand guide gives you a hex triplet, a design tool wants HSL because that is what makes a tint ramp legible, CSS wants whichever of the two you find easier to read six months from now, and something in the pipeline still expects three integers.
The tools here do those conversions exactly rather than approximately, and pull palettes out of images you already have. Nothing about colour needs a server, so nothing here uses one.