I did this keychains to be printed in two colors

I used Cura and with 0.2mm of height i have 20 layers. I start printing with Black color and then i need to add two "Pauses at Height" for filament change. You can do it modifying the G-Code from the option on Cura (Extensions -> Postprocessing -> Modify G-Code)

At layer 10 with this parameters (Only modify these) -Park Printhead X: 15 -Park Printhead Y: 15 -Retracction: 40 -Extrude amount: 70 (Or the value to get the more previos color out from nozzle) -Standby Nozzle Teperature: 200°C (or the print temp you use for your filamet) Change to White filament

At layer 15 with same previous parameters change to black filamernts for final details