如何将标签放在图片框后面，以便在图片框c＃下看到标签？

My problem is like that: I have a Windows Form Application and it contains a picture which is in a picturebox. The picture contains mostly transparent parts and picture box is also transparent. So when I change backgroundcolor property of form, picture background changes also. But I want to put many labels behind picturebox, and when I change backgroundcolor of any label, it should be seen behind the picturebox and only as color of transparent part.My problem is like that: I have a Windows Form