Any color can be quantified with its hue (H), (from 0 to 360), Saturation (S) or chroma (from 0 to 100), and value (V) (from 0 to 100). HSV are called the coordinates of the color. If you know HSV of a color, you can plot that color in the 3D color space. If you know H and S, you can plot the color on the color wheel.
This app is a tool to show your color(s) on the color wheel. You type in (or scroll up and down) the Hue (H) and Chroma (S), then the color will show up on the color wheel below. To add more color(s), click "add color" button, then input H and S, then check the box.
I want to thank my friends Danmin Fu and Guoling Gu for developing this app. If you see any issues, please contact me.