js functions to convert between hex string and rgb object colors

gistfile1.js

function hexToRgb(hex)
{
    var res = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
    return res ? { 
        r: parseInt(res[1], 16),
        g: parseInt(res[2], 16),
        b: parseInt(res[3], 16)
    } : null;
}

function rgbToHex(r, g, b)
{
    return ((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1);
}