更新：
GitHub上的生产就绪代码.
我就是这样做的：
>将HEX转换为RGB
>反转R,G和B组件
>将每个组件转换回HEX
>用零和输出填充每个组件.
function invertColor(hex) {
if (hex.indexOf('#') === 0) {
hex = hex.slice(1);
}
// convert 3-digit hex to 6-digits.
if (hex.length === 3) {
hex = hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2];
}
if (hex.length !== 6) {
throw new Error('Invalid HEX color.');
}
// invert color components
var r = (255 - parseInt(hex.slice(0, 2), 16)).toString(16),
g = (255 - parseInt(hex.slice(2, 4), 16)).toString(16),
b = (255 - parseInt(hex.slice(4, 6), 16)).toString(16);
// pad each with zeros and return
return '#' + padZero(r) + padZero(g) + padZero(b);
}
function padZero(str, len) {
len = len || 2;
var zeros = new Array(len).join('0');
return (zeros + str).slice(-len);
}
示例输出：
高级版：
这有一个bw选项,决定是否反转为黑色或白色;所以你会得到更多的对比度,这对人眼来说通常更好.
function invertColor(hex, bw) {
if (hex.indexOf('#') === 0) {
hex = hex.slice(1);
}
// convert 3-digit hex to 6-digits.
if (hex.length === 3) {
hex = hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2];
}
if (hex.length !== 6) {
throw new Error('Invalid HEX color.');
}
var r = parseInt(hex.slice(0, 2), 16),
g = parseInt(hex.slice(2, 4), 16),
b = parseInt(hex.slice(4, 6), 16);
if (bw) {
// http://stackoverflow.com/a/3943023/112731
return (r * 0.299 + g * 0.587 + b * 0.114) > 186
? '#000000'
: '#FFFFFF';
}
// invert color components
r = (255 - r).toString(16);
g = (255 - g).toString(16);
b = (255 - b).toString(16);
// pad each with zeros and return
return "#" + padZero(r) + padZero(g) + padZero(b);
}
示例输出：
