change canvas background color three js code example

Example 1: three.js renderer background color

var scene = new THREE.Scene(); // initialising the scene
scene.background = new THREE.Color( 0xff0000 );

Example 2: canvas set background color

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
ctx.fillStyle = "blue";
ctx.fillRect(0, 0, canvas.width, canvas.height);