The Labels pane of World Clock Deluxe Settings (macOS 13 or later) or World Clock Deluxe Preferences (macOS 12 or earlier) lets you customize labels and choose how label colors are used in your clocks. With labels can easily single out your local clock or different groups of clocks.
Click and use the Colors window to specify a color.
Type a label name.
Choose how labels should appear in the Clocks palette and, if you rotate clocks in the Dock, in the Dock icon. Choose Background, Frame, or Text to use label colors for your clocks' background, frame, or text, respectively.