https://coloratom.com/
Color Atom is the lab for color exploration. Pick any color, export it in HEX, RGB, HSL or HSV formats, preview how it reads, create variations and themes, and...
coloratomonepickerlab
https://github.com/martin-stone/hsv-alpha-color-picker-android
A color picker and a color preference for use in Android applications. - martin-stone/hsv-alpha-color-picker-android
martin stonecolor pickergithubhsvalpha