JSFiddle - React, Tailwind, and code Playground

HTML

<div class="mydiv"></div>

CSS

.mydiv{
	width:200px;
	height:100px;
}

JavaScript

Element.prototype.setGradient = function( fromColor, toColor ){
	var canvas = document.createElement('canvas');
	var ctx    = canvas.getContext('2d');
	var b      = this.getBoundingClientRect();
	var grd    = ctx.createLinearGradient(0, 0, b.height*2, 0);
	
	grd.addColorStop(0, fromColor);
	grd.addColorStop(1, toColor);

	ctx.fillStyle = grd;
	ctx.fillRect(0, 0, b.width, b.height);

	this.style.backgroundImage = 'url('+canvas.toDataURL()+')';
}

document.querySelector('.mydiv').setGradient('red','green');