Folding Box

UPDATE: Here is a link to a parameterized version of this design in OnShape. Use the "Configurations" pane to change the three dimensions of the box and then export to STL by right clicking on the "box" part in the "Parts" pane.

https://cad.onshape.com/documents/89ee1fae0b44d3ba51374deb/w/8c6c8751f8fadaf05afa6176/e/335e7697609945060bea23a9

A box you fold up like cardboard. The final size is about 50x50x25mm and can print on a bed at least 180x180mm. Printing dual color boxes is easy with 0.1 layer height and 0.2 for the first layer. Set the color change after layer 2, which gives you 0.3mm of the first color (outside) and 0.2mm of the second color (inside).

UPDATE: v2 update adds additional space to make it easier to get the tabs into the slot.