jQuery set CSS background opacity

Question

I have a

whose transparency of its background-color (and not its contents) I\'d like to change. A remote API sends me this colour:

Answer 1

You may try this

function convertHex(hex,opacity){
    hex = hex.replace('#','');
    r = parseInt(hex.substring(0,2), 16);
    g = parseInt(hex.substring(2,4), 16);
    b = parseInt(hex.substring(4,6), 16);
    result = 'rgba('+r+','+g+','+b+','+opacity/100+')';
    return result;
}

$('h1').css('background', convertHex('#A7D136', 0.5));

An example here.