Get a contrasting colour. Put a black label on a light background, a white label on a light one. For example.

contrastColour

/**
 * @param hex {String} hex colour with or without hash
 * @returns {String} black if the original colour was light, white if it was dark. With hash if it had it in the first place.
 */
 
 getContrastMonochrome = function (hex) {
    var colour = hex,
        sum,
        hasHash = false;
    hex = hex.charAt(0) === "#" ? hasHash = hex.substring(1) : hex;
    sum = (function(h){
        var sum = 0;
        for(var i = 0; i < h.length; i+=2){
            sum += parseInt(h.substr(i,2),16);
        }
        return sum;  
    })(hex);
    // yeah yeah, magic number
    // you can replace it with 
    // (parseInt("ff", 16) * 3) / 2
    // if you really want
    colour = sum > 382 ? "000000" : "ffffff";
    if(hasHash) { 
      colour = "#" + colour;
    }
    return colour;
};