Viewer background
Click the color button to choose the background color of the viewer window.

Thumbnail background
Click the color button to choose the color of the rectangular background area of each thumbnail.

3D thumbnail frame
If checked, the thumbnail background rectangles will be given a 3-dimensional frame. Leave this box unchecked for a flat background area.

Thumbnail selector
Click the color button to choose the color of the selector-box drawn around the currently-selected thumbnail.

Thumbnail dimensions
Drag the slider to the left or right to decrease or increase the size at which thumbnails are displayed. This also affects the size at which thumbnails are saved using the two Save options on the Tools menu: the saved images have the same dimensions as their thumbnails in the browser.