渲染纹理时颜色错误

完整代码:

import GameKit
import SpriteKit
import PlaygroundSupport

let source = GKPerlinNoiseSource()
let noise = GKNoise(source)
noise.gradientColors = [-1: #colorLiteral(red: 0.7537418008, green: 0.4404714704, blue: 0.2776784003, alpha: 1) , 1: #colorLiteral(red: 0.2008953691, green: 0.186568588, blue: 0.2595013976, alpha: 1)]
let map = GKNoiseMap(noise, size: vector2(1.0, 1.0), origin: vector2(0.0, 0.0), sampleCount: vector2(Int32(256), Int32(256)), seamless: false)
let texture = SKTexture(noiseMap: map )


let ball = SCNSphere(radius: 1)
let materials = SCNMaterial()
materials.diffuse.contents = texture
ball.materials = [materials]
var node = SCNNode(geometry: ball)


var sceneView = SCNView(frame: CGRect(x: 0, y: 0, width: 300, height: 300))
var scene = SCNScene()
sceneView.scene = scene
PlaygroundPage.current.liveView = sceneView

var cameraNode = SCNNode()
cameraNode.camera = SCNCamera()
cameraNode.position = SCNVector3(x: 0, y: 0, z: 3)
scene.rootNode.addChildNode(cameraNode)
scene.rootNode.addChildNode(node)