JSFiddle - React, Tailwind, and code Playground

by Julien Etienne

JavaScript

const hextoRgb3 = hex => {
  let r = 0x0
  let b = 0x0
  let g = 0x0
  
  hex.startsWith('#') && (hex = hex.slice(1))
  let num = parseInt(hex, 16)
  
  if (num <= 0xFFF) {
    b = num & 0xF
    b |= b << 4
    num >>= 4
    g = num & 0xF
    g |= g << 4
    num >>= 4
    r = num
    r |= r << 4
  } else {
    b = num & 0xFF
    num >>= 8
    g = num & 0xFF
    num >>= 8
    r = num
  }
  return `rgb(${r},${g},${b})`
}

	
var b = hextoRgb3("#123")
var a= hextoRgb3("#123123")

console.log(a,b)