Changing SpriteRenderer MPB distorts sprite

Would anyone know why changing the color of a sprite using the material property block of the renderer will distort it?

```
var renderer = GetComponent<SpriteRenderer>();
MaterialPropertyBlock mbp = new MaterialPropertyBlock();
mbp.SetColor("_Color", color);
renderer.SetPropertyBlock(mbp);
```



White one is not modified, red one is after color is applied.

Of course, this can be avoided by using `SpriteRenderer.color` instead but just curious as to why this happens. Thanks.