7 Segment Display - Hiding the electronics
You could mask off the section of the box above the 7-segment displays and then spray-paint the inside of the box to whatever color you like.  If the alignment is correct, you'll just see the display.

Alternately (or additionally), take a piece of black paper or card stock and carefully cut out holes for the individual displays.  Slide the paper over the PCB, and you'll be covering up your electronics.  You could even add labels (or a logo) to the paper, if necessary.