OK Erel, I found it out now myself:
First in activity Main a panel1 over the whole screen. There I handle the colors.
In this a panel2, set to transparent, all that saved as Layer1 (I missed this step in my project, loadet layer2 in panel1, and that was the reason, it did not work.)
A new layer2, with a panel3 all over activity-size.
Load this layer2 in panel2.
Thank you for your help!