需要获取颜色的图片以走下角为起点建立空物体 右上角建立空物体（两个空物体均设置为图片的子物体，设置好锚点，将坐标改为0即可）。建立好碰撞体（BoxCollider)。用2DBoxCollider的话从摄像机发射的射线无法检测到图片。

实现：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;public class MouseChooseColorTest : MonoBehaviour
{//选择颜色时用来检测是否是点击的选择颜色的图片//public RayMake rayMake;//计算鼠标点击位置 对应的像素位置public Transform textureOrigin;public Transform textureUPEnd;//存储点击的图片的texture2D getpixel() 使用private Texture2D clickTexture2D;//存储鼠标点击位置的像素值private Color testColor;//存储计算出来的像素点的位置private Vector2 colorPos;//存储图片定位点的屏幕坐标private Vector3 textureOriginScreenPosition;private Vector3 textureEndUPScreenPosition;//测试用的显示颜色的图片public Image image;private void Start(){//rayMake.RayHitObj += HitColorChooseImage;textureOriginScreenPosition = Camera.main.WorldToScreenPoint(textureOrigin.position);textureEndUPScreenPosition = Camera.main.WorldToScreenPoint(textureUPEnd.position);}private void HitColorChooseImage(RaycastHit hit){if (hit.collider.name=="ColorChoose"){clickTexture2D =  hit.collider.gameObject.GetComponent<Image>().sprite.texture;CaculateVector();testColor = clickTexture2D.GetPixel((int)colorPos.x,(int)colorPos.y);image.color = testColor;}   }private void CaculateVector(){colorPos.x = (Input.mousePosition.x - textureOriginScreenPosition.x) / (textureEndUPScreenPosition.x - textureOriginScreenPosition.x) * clickTexture2D.width;colorPos.y = (Input.mousePosition.y - textureOriginScreenPosition.y) / (textureEndUPScreenPosition.y - textureOriginScreenPosition.y) * clickTexture2D.height;}
}

HitColorChooseImage(RaycastHit hit)，该方法写入射线检测即可。 主要解决问题是计算鼠标位置的像素的坐标。