@coreui/coreui-pro/js/src/utilities/rgb-to-hex.js

UI Kit built on top of Bootstrap 4

/**
 * --------------------------------------------------------------------------
 * CoreUI (v2.1.14): rgb-to-hex.js
 * Licensed under MIT (https://coreui.io/license)
 * --------------------------------------------------------------------------
 */

/* eslint-disable no-magic-numbers */
const rgbToHex = (color) => {
  if (typeof color === 'undefined') {
    throw new Error('Hex color is not defined')
  }
  if (color === 'transparent') {
    return '#00000000'
  }
  const rgb = color.match(/^rgba?[\s+]?\([\s+]?(\d+)[\s+]?,[\s+]?(\d+)[\s+]?,[\s+]?(\d+)[\s+]?/i)
  if (!rgb) {
    throw new Error(`${color} is not a valid rgb color`)
  }
  const r = `0${parseInt(rgb[1], 10).toString(16)}`
  const g = `0${parseInt(rgb[2], 10).toString(16)}`
  const b = `0${parseInt(rgb[3], 10).toString(16)}`

  return `#${r.slice(-2)}${g.slice(-2)}${b.slice(-2)}`
}

export default rgbToHex