Stepper motor must be Nema 17, it is a size standard, it is sold by different manufacturers. There are 2 variants shaft 5mm round and bevelled edge this is what you should look for. The shaft should be around 20 mm long, there are several variants here as well. Furthermore, there are not always contacts on the cord, so it is good so you do not have to put it on yourself since the cord is not too short, on mine they are 30cm shorter than so they should not be, preferably a little longer. Below link to one that. There are certainly in several places buy what suits you depending on where in the world you live.

If the distance (Stepper ‐ motor ‐ distance.stl) does not fit the one you get, say, I will post a custom one. The shaft protrudes 18mm above the plate, with my stepper motor.

The trick to mounting the RGB lighting in the right place. Do this, attach the bracket to the box with double-sided adhesive tape (without the diffusion disc), push in the bracket a few millimeters. Place the drawer in the right place on the plate and press down on the bracket on the plate the bracket gets stuck and you can remove the drawer.

The pictures show earlier, version of RGB lighting, 3D print parts are updated.

The RGB LED is screwed to the metal plate and thus gets very good cooling. Before painting, apply a piece of electrical tape as shown in the picture

so there is a clean metal surface to attach the RGB LED to.

Attach a piece of aluminum foil, with 2 pieces of double-sided adhesive tape. This then becomes a reflector for the light.

All pieces must be mounted centrally.