Check out example codes for "css color picker". It will help you in understanding the concepts better.

Code Example 1

color pick by osp pro.

Code Example 2

paletton is what you want
It even gives you presets based on the colour rules
See below link

Code Example 3

pycharm = #4a4a42
indigo = #0ef0d2
blue(dark ) = #1215de
blue (light ) = #229ce3
red = #de120b
pink = #e809e1
purple = #9010eb
green (dark) = #1aff00
green (light) = #76e83c
orange = #eb7b0c
yellow = #e9ed09

Code Example 4

color picker

Code Example 5

<input id="colorPicker" type="color" value="#ff0000">

Code Example 6

10, 103, 171

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