export const colorIsDark = color => { if (color === '#' || color === '') { return true // Defaults to dark } if (color.substring(0, 1) !== '#') { color = '#' + color } let rgb = parseInt(color.substring(1, 7), 16) // convert rrggbb to decimal let r = (rgb >> 16) & 0xff // extract red let g = (rgb >> 8) & 0xff // extract green let b = (rgb >> 0) & 0xff // extract blue // luma will be a value 0..255 where 0 indicates the darkest, and 255 the brightest let luma = 0.2126 * r + 0.7152 * g + 0.0722 * b // per ITU-R BT.709 return luma > 128 }