You can use it here.
Why do I like it?
- It uses oklch which currently seems to be the best way to define colours on the web (coming in CSS 5).
- It shows you quite a lot of contrast options.
- It generates CSS variables (as hex, not oklch, but still very nice).
- It shows you a lot of cool graphs for values that actually matter when you try to make a color scheme (like perceived lightness).
Overall, very much recommend to try!