I designed this sign for the fun.

I wanted my version of the "Keep Calm ..." sign with a helicopter, so here's my little contribution.

To print it in two colors, I paused at the end of printing the last layer of white to change the filament and switch to a black filament.

I have attached the 3 STL files: one which contains the entire plate, and the other two which will allow working on dual extrusion printers.