如何给一个立方体的面分别定义颜色

function createNormalMateril(){

    var cubeMaterialArray = [];

    cubeMaterialArray.push( new THREE.MeshBasicMaterial( { color: 0x45beac,transparent:true,opacity:0.5 } ) );

    cubeMaterialArray.push( new THREE.MeshBasicMaterial( { color: 0x45beac,transparent:true,opacity:0.6 } ) );

    cubeMaterialArray.push( new THREE.MeshBasicMaterial( { color: 0x45beac,transparent:true,opacity:0.7 } ) );

    cubeMaterialArray.push( new THREE.MeshBasicMaterial( { color: 0x45beac,transparent:true,opacity:0.7 } ) );

    cubeMaterialArray.push( new THREE.MeshBasicMaterial( { color: 0x45beac,transparent:true,opacity:0.4 } ) );

    cubeMaterialArray.push( new THREE.MeshBasicMaterial( { color: 0x45beac,transparent:true,opacity:0.5 } ) );

    return new THREE.MeshFaceMaterial( cubeMaterialArray );

}