RGB 转化为十六进制

[js]
function zero_fill_hex(num, digits) {
var s = num.toString(16);
while (s.length < digits)
s = "0" + s;
return s;
}

function rgb2hex(rgb) {

if (rgb.charAt(0) == '#')
return rgb;
var n = Number(rgb);
var ds = rgb.split(/\D+/);
var decimal = Number(ds[1]) * 65536 + Number(ds[2]) * 256 + Number(ds[3]);
return "#" + zero_fill_hex(decimal, 6);
}
rgb2hex('rgb(255, 255, 255)');
[/js]