Hi,
This is a seperate post for the Sport 7 segment displays that you can print with the diffuser together. The diffuser consists of a single layer of white PLA, but maybe a darker colour can be better for better contrast. Segments include 2 or 1 yellow LEDs depending of the size. I glued the segments to back piece but you can make it friction fit if you fiddle with scale like up like %101 but not worth bothering imo. Definitely have a test print with one segment first to confirm that it fits the back piece or scale the backpiece down or up after printing the segments.

The 7 segment design in not mine but I made them 3D printable: http://www.michieldb.nl/other/segments/
Check the clock application of these displays for extra details: https://www.thingiverse.com/thing:6684505

You print them face down like shown in the image. You can skip the diffuser layer being different colour and print all at once but I think it looks nice when the front layer is different colour. Also be careful that you do not have gaps in your first layer since LEDs will shine through. I unfortunately have some on some of my segments. If you want to change colour after the first layer you either need a printer that does not shut off the steppers when paused or simply use the G4 command in Gcode to put a pause command after the first layer to change the filament.

Check the video for the clock to see the displays in action: https://www.youtube.com/watch?v=VrYwxv41JsA&t=730s