Your ambient light configuration was not correct. The intensity value was again way too hight. Try it with:
var ambientLight = new THREE.AmbientLight( 0xffffff, 0.6 );
scene.add( ambientLight );
Besides, you should also configure the renderer to output sRGB for proper colors:
renderer.outputEncoding = THREE.sRGBEncoding;
It looks then like so:
