It's an 8-bit heart, ready for Dual extrusion! Looks great on a key chain!
In Cura you can load both files into the platform and right click one and select "Dual Extrusion Merge" provided you have two extruders on your machine.
Merge both .stl files to make up your gcode file... or just use the supplied s3g file on your sd card with Dual Extrusion Replicator.
Notes about s3g file. I have it set to 5% fill, and heated build platform set to 115 temp, the border uses Left extruder and the infill uses Right.