This can be printed just by changing the filament at the right levels. I printed this as follows;

Layer 1 0.3

All other layers 0.2

Colour Changes

0 - White

4 - Dark Blue

12 - Light Blue

15 - Red

19 - Black

22 - Light Blue (or any other colour for the Clock Numbers

It has an 8mm hole for the quartz clock mechanism

It is quite an easy print specially with Prusaslicer which has an automatic colour change detect slicer mode which lets you see each colour before you upload to your printer.