My first attempt at a new processes of dual color printing with a single extruder. The logo was sliced and printed two layers high (.4mm). I then used blender to create a negative in the S4 case. The case was sliced up with a starting height of .45mm. This prevented any collision with the first print, and allowed some overlap to bond the two prints together.
Video links:
Maybe I’m understanding you wrong but: If you started printing the red part at 0.45mm height, how did you get it to stick to the bed at all?
My guess is exaggerating layer 1 extrusion percentage for the red.
Thickness .45 not Y position. He cut a negative space out of the red to fit the logo. Details in his videos. I know TL;DW
Nah, no sound with the videos, at work 
Gina - for the black layer I used a .35mm dia nozzle, a layer height of .2mm, and two two layers thick (resulting in a part that is .4mm tall). I then swapped to my .5mm nozzle and used slic3r and sliced the phone. Inside slic3r I specified my first layer height to be .45mm tall, and the rest of the layers be .3mm high. Even though I made a negative in the phone case of the logo I wanted to be sure that the nozzle was taller than the first print to prevent possible collision issues. A starting height of .45mm is not difficult for a .5 nozzle slic3r takes the height into consideration and adjusts your extrusion width. The end result is a fatter/taller extrusion.
Aaaaah, OK… I somehow managed to forget about a simple bigger nozzle diameter and had a 0.4mm one in mind (which is the one I use), with which a 0.45mm layer height of course wouldn’t have made sense. Thanks for clarifying and grats for the stunning result 
