Javascript functions for doing fast binary/hex/RGB color conversions using bitwise operations.

bitcolor.js

// convert 0..255 R,G,B values to binary string
RGBToBin = function(r,g,b){
    var bin = r << 16 | g << 8 | b;
    return (function(h){
        return new Array(25-h.length).join("0")+h
    })(bin.toString(2))
}

// convert 0..255 R,G,B values to a hexidecimal color string
RGBToHex = function(r,g,b){
    var bin = r << 16 | g << 8 | b;
    return (function(h){
        return new Array(7-h.length).join("0")+h
    })(bin.toString(16).toUpperCase())
}

// convert a 24 bit binary color to 0..255 R,G,B
binToRGB = function(bin){
    var pbin = parseInt(bin,2);
    var r = pbin >> 16;
    var g = pbin >> 8 & 0xFF;
    var b = pbin & 0xFF;
    return [r,g,b];
}

// convert a hexidecimal color string to 0..255 R,G,B
hexToRGB = function(hex){
    var r = hex >> 16;
    var g = hex >> 8 & 0xFF;
    var b = hex & 0xFF;
    return [r,g,b];
}

// simple log function for web/nodejs
log = function(item){
    if (document.body){
        document.body.innerHTML = document.body.innerHTML+'<pre>'+item+'</pre>';
    } else {
        console.log(item);
    }
}

// convert some RGB color values to hex and to binary
new Array(
    [000,000,000], // black
    [000,255,000], // green
    [255,255,255]  // white
).forEach(function(rgb){
    var hex = RGBToHex(rgb[0],rgb[1],rgb[2]);
    var bin = RGBToBin(rgb[0],rgb[1],rgb[2]);
    log('-> RGB: '+rgb+' \n<- HEX: '+hex+' \n<- BIN: '+bin+'\n\n');
});

// convert some hexidecimal color values to RGB
new Array(
    '000000', // black
    '00FF00', // green
    'FFFFFF'  // white
).forEach(function(hex){
    var rgb = hexToRGB(parseInt(hex,16));
    log('-> HEX: '+hex+' \n<- RGB: '+rgb+'\n\n');
});

// convert some 24 bit binary color values to RGB
new Array(
    '000000000000000000000000', // black
    '000000001111111100000000', // green
    '111111111111111111111111'  // white
).forEach(function(bin){
    var rgb = binToRGB(bin);
    log('-> BIN: '+bin+' \n<- RGB: '+rgb+'\n\n');
});

Does the hexToRGB function do shorthex values as well?

UPDATE, it does not. I would suggest to do a check if length is less than 7 characters, if not duplicate each alphanumeric.

the hex needs to start with "0x", for those who couldn't get it working

Array(7-h.length).join("0") can be replaced with "0".repeat(6-h.length)