How to get "pixel" color for Sprite (U4.3)?

Concept: Grab a sprite, grab the texture of the sprite, scan the texture.

But first, change your import settings to Advanced and enable read and write.

Execution:

 private Texture2D myTexture;
 private Sprite mySprite;
 
 void Start(){
 mySprite = gameObject.GetComponent<SpriteRenderer>().sprite;
 myTexture = mySprite.texture;
 Color MyPixel = myTexture.GetPixel(x,y);
 
 }

This will get a pixel's color from a Sprite's texture without using colliders. This is based on casting a ray from a mouse position to get the pixel's color. Note that this gets the texture's color, not the color as processed by the material's shaders. It also requires that your texture have the Read/Write option enabled in the inspector settings or it will throw an error. It works in 2D orthographic and 3D perspective.

(This was adapted from a sprite selector I just wrote that uses the same technique to select the sprite by clicking on any opaque pixel in the sprite, ignoring transparent pixels.)

Note: This will not work on PVRTC texture compression because texture.GetPixel is not supported.

 public bool GetSpritePixelColorUnderMousePointer(SpriteRenderer spriteRenderer, out Color color) {
     color = new Color();
     Camera cam = Camera.main;

     Vector2 mousePos = Input.mousePosition;
     Vector2 viewportPos = cam.ScreenToViewportPoint(mousePos);

     if(viewportPos.x < 0.0f || viewportPos.x > 1.0f || viewportPos.y < 0.0f || viewportPos.y > 1.0f) return false; // out of viewport bounds

     // Cast a ray from viewport point into world
     Ray ray = cam.ViewportPointToRay(viewportPos);
     
     // Check for intersection with sprite and get the color
     return IntersectsSprite(spriteRenderer, ray, out color);
 }

 private bool IntersectsSprite(SpriteRenderer spriteRenderer, Ray ray, out Color color) {
     color = new Color();
     if(spriteRenderer == null) return false;

     Sprite sprite = spriteRenderer.sprite;
     if(sprite == null) return false;

     Texture2D texture = sprite.texture;
     if(texture == null) return false;

     // Check atlas packing mode
     if(sprite.packed && sprite.packingMode == SpritePackingMode.Tight) {
         // Cannot use textureRect on tightly packed sprites
         Debug.LogError("SpritePackingMode.Tight atlas packing is not supported!");
         // TODO: support tightly packed sprites
         return false;
     }

     // Craete a plane so it has the same orientation as the sprite transform
     Plane plane = new Plane(transform.forward, transform.position);

     // Intersect the ray and the plane
     float rayIntersectDist; // the distance from the ray origin to the intersection point
     if(!plane.Raycast(ray, out rayIntersectDist)) return false; // no intersection

     // Convert world position to sprite position

     // worldToLocalMatrix.MultiplyPoint3x4 returns a value from based on the texture dimensions (+/- half texDimension / pixelsPerUnit) )
     // 0, 0 corresponds to the center of the TEXTURE ITSELF, not the center of the trimmed sprite textureRect
     Vector3 spritePos = spriteRenderer.worldToLocalMatrix.MultiplyPoint3x4(ray.origin + (ray.direction * rayIntersectDist));

     Rect textureRect = sprite.textureRect;

     float pixelsPerUnit = sprite.pixelsPerUnit;
     float halfRealTexWidth = texture.width * 0.5f; // use the real texture width here because center is based on this -- probably won't work right for atlases
     float halfRealTexHeight = texture.height * 0.5f;

     // Convert to pixel position, offsetting so 0,0 is in lower left instead of center
     int texPosX = (int)(spritePos.x * pixelsPerUnit + halfRealTexWidth);
     int texPosY = (int)(spritePos.y * pixelsPerUnit + halfRealTexHeight);

     // Check if pixel is within texture
     if(texPosX < 0 || texPosX < textureRect.x || texPosX >= Mathf.FloorToInt(textureRect.xMax)) return false; // out of bounds
     if(texPosY < 0 || texPosY < textureRect.y || texPosY >= Mathf.FloorToInt(textureRect.yMax)) return false; // out of bounds

     // Get pixel color
     color = texture.GetPixel(texPosX, texPosY);

     return true;
 }