I have read question about "how to make transparent panel on ubuntu?" on one computer magazine. The answer just by text only without example picture. So I make example about it with picture. Maybe you also want to know how to make transparent panel on Sabily. This method is same on Ubuntu too.
01. First, right click on the Panel. Then click on Properties.
02. Click on Background menu. Select Solid color.
03. Drag the Style to Transparent. Your panel now transparent.
04. You also can use picture for your panel background by select Background image. Then locate the image that you like. Now your panel use background image.
You can create more Panel by click on New Panel after right click on the Panel.