Gradientowy

var elems = document.body.getElementsByTagName("*");

function getRandomInt(min, max) {
  min = Math.ceil(min);
  max = Math.floor(max);
  return Math.floor(Math.random() * (max - min)) + min;
}

function getRandomRGB() {

    return "rgb("+ getRandomInt(0, 255) +", "+ getRandomInt(0, 255) +", " + getRandomInt(0, 255) +")"

}

var directions = ["to left", "to bottom", "to right", "to top"]


for(var i = 0; i < elems.length; i++) {


    numbero = getRandomInt(0,directions.length + 5)

    if(numbero <= directions.length-1) {
        direction = directions[numbero];
    } else {
        direction = getRandomInt(0, 360) + "deg"
    }

    gradient = "linear-gradient("+ direction + ", " + getRandomRGB() + ", " + getRandomRGB() + " , " + getRandomRGB() + ")";

    elems[i].style.backgroundImage = gradient;

    }


    $(function () { $(".board").attr('style', 'background-image: ' + gradient + ' !important;');});