One of the challenges of having a 3D printer with just one extruder is the desire for multiple colors in a print. I struggled with that on my last printer a lot. It turns out upgrading my printer made the ability to add multiple colors to a print so much easier.
DUAL COLOR PRINTS WITH A SHARPIE
The trick to this one is to get a Sharpie and color your filament before it goes into the extruder. White filament works best for this. The colors come out in a pastel hue. This may work for certain prints, but I was never happy with the results and the PIA it was to actually color the filament correctly to get a consistent color spread.
DUAL COLOR PRINTS BY SWAPPING FILAMENT MID PRINTThis is the preferred way to do it. My new printer automagically remembers where it left off when I pause the print and change out the filament. The key is to knowing at what layer you want to pause to change over to a diferent color. The fidget spinners below took two changes (One at layer 21 and another at layer 25 to give it a pin stripe look).
I'd recommend trying the mid print "stop n' swap" if you can. Test it a few times to get the process down on a 10mm by 10mm by 10mm cube.Happy printing