The System - Transparency page of the Preferences dialog
The System – Transparency page of the Preferences dialog allows you to control the transparency of floating windows and toolbars.
This page is accessed by clicking Transparency under the System folder in the main Preferences dialog (accessed by clicking the button in the top right corner of the workspace).
Transparent floating windows - enable this option to automatically make all floating toolbars and windows that are over the workspace transparent when an interactive process is invoked. If this option is enabled, the Files panel is made transparent.
Dynamic transparency - enable this option to dynamically set the transparency of floating toolbars and windows. The system uses the distance of each window from the cursor to calculate its transparency. If this option is enabled, whenever the cursor is moved toward a dialog, the dialog becomes transparent. Use the Distance factor slider to determine the distance at which the transparency 'kicks in'.
Sliding Transparency Controls
Highest transparency - move this slider to the right for maximum transparency whenever a cursor approaches the floating window.
Lowest transparency - move this slider to the right for minimum transparency whenever a cursor is moved away from the floating window.
Use the Highest transparency and Lowest transparency bars in conjunction with each other to control how transparent the windows and panels appear. For example, both bars to the far right means a floating window becomes completely transparent when an interactive process is in the way; both bars to the far left means the floating window is not transparent.
Distance factor - use this slider to determine the distance between the cursor and the floating window (dialog or panel) at which the transparency 'kicks in'. Move this slider to the left to set a smaller distance and to the right for a larger distance.