Quick and dirty function for scraping colors from web page

getAllColors.js

function getAllColors() {
  const COLOR_CONTAINING_PROPERTIES = ["backgroundColor", "borderTopColor", "borderRightColor", "borderLeftColor", "borderBottomColor", "color"]

  let colors = []
  let elements = document.querySelectorAll('*')

  elements.forEach(element => {
    const styles = window.getComputedStyle(element)

    COLOR_CONTAINING_PROPERTIES.forEach(property => {
      const color = styles[property]

      if (color && !colors.includes(color)) {
        colors.push(color)
      }
    })
  })

  const div = document.createElement('div')
  
  div.style.position = 'fixed'
  div.style.left = 0
  div.style.top = 0
  div.style.backgroundColor = '#fff'
  div.style.width = '392px'
  div.style.display = 'flex'
  div.style.flexWrap = 'wrap'
  div.style.border = 'solid 1px #000'
  div.style.zIndex = 1000000
  
  document.body.appendChild(div)

  colors.forEach(color => {
    const colorDiv = document.createElement('div')

    colorDiv.style.width = '30px'
    colorDiv.style.height = '30px'
    colorDiv.style.margin = '0'
    colorDiv.style.backgroundColor = color

    div.appendChild(colorDiv)
  })

  return colors
}