My solution to the JS Refactor Challenge w/ comments

var html = '',
    rgbColor;

/*
function that creates a random combination of
red, blue and green values and then stores them
in the rgbColor variable
*/
function rgbCreator() {
    var red = Math.floor(Math.random() * 256 ), // creates random shade of red
        green = Math.floor(Math.random() * 256 ), // random shade of green
        blue = Math.floor(Math.random() * 256 ); // random shade of blue
    rgbColor = 'rgb(' + red + ',' + green + ',' + blue + ')';
}

/*
for loop which calls the rgbCreator() function to
create a new rgb value each time it loops. Each time
it adds a new div to the html variable with the 
randomly generated color
*/
for (var i = 0; i < 10; i++) {
  rgbCreator();
  html += '<div style="background-color:' + rgbColor + '"></div>';
}

document.write(html);