If you want to make the Clocks palette less evident on your desktop you can reduce your clocks' opacity.
On macOS 13 or later, choose World Clock Deluxe > Settings. On macOS 12 or earlier, choose World Clock Deluxe > Preferences. Then click Palette.
Drag the Opacity slider.
By default, transparency affects both background and text. If you want to keep the text (and hands, if clocks are analog) opaque, select the "Don't apply transparency to text" checkbox.
Transparent clocks become opaque when you move the mouse pointer over the Clocks palette.
Control-click the palette's background and choose a value (20%, 30%, 40%, ... , 100%) from the Opacity submenu of the shortcut menu.