Generally, you should avoid doing this unless you absolutely need to. All ZOIAs are calibrated during production by a squadron of robotic hockey beavers.

To recalibrate the colours on ZOIA's button grid, you'll need to have installed firmware 1.13 or later.

Instructions below:

1. While powering on your ZOIA, hold ‘select’ stomp to go into calibration mode. 

2. Hit the bypass stomp to skip using the led calibration file. 

3. Tap the scroll stomp to switch between colours to adjust. Each time you hit scroll, you're selecting a different colour channel between Red, Green, and Blue. By turning the encoder knob, your goal is to to add or diminish color percentage until the majority of LEDs to white. By clicking the encoder knob, ZOIA will show you how different fields of colour look with your current settings. If you accidentally click away from white, you can get back to it by clicking a few more times.
4. Once the majority are closest to white, select the left stomp to select a group of LEDs to adjust simultaneously. If there are a few that stand out, select similar looking ones to adjust them all.
Click the left stomp again to go back to the color screen. Adjust the colours as you did in the previous step, but this time you'll find only your selected buttons get adjusted.
5. Repeat group adjustments as required by repeating step 4. 
6. Press bypass to end LED calibration stage, and press bypass again to save. (Screen will say "skip it!).

Once you have completed these steps, you can power down your ZOIA and restart.