Have some AA batteries rolling around? Here's a box that can hold up to 10 AA batteries. The lid holds on using a friction fit, and there are grooves to grab onto in order to open the box.
If you want to achieve the multi color print that I have shown above, this is the manual procedure I use. Alternatively, you can use Marlin's "advanced pause."
1) Figure out which layer you want the secondary color to begin at in your slicer preview.
2) Save the .gcode and open it in a text editor such as Notepadd++.
3) Find your layer using CRTL + F "Layer xx"
4) Insert the following code just before the start of the new layer:
G91 ; Set Coordinates to relative to last position
G1 Z10 ; Raise nozzle 10mm
G90 ; Set Coordinates back to absolute to origin of machine
G1 X0 ; Home X axis
M0 Click To Restart ; Pause and wait for the user
G91 ; Put in relative mode
G1 Z-10 ; Return nozzle down 10mm
G90 ; Put back in absolute mode
5) If you want to change filament again, repeat the procedure from step 1).