Hello Peter,
There is currently no way of calibrating the eye tracker with the EyeX SDK, but you could always use the GazeSDK for this.
Be aware that there might be troublesome to make your own calibration work with the EyeX controller if the EyeX engine is running, since there is no guarantee when the EyeX engine decides to reload the current profile’s calibration.
I will forward this to the product owner, to see if we can make the contrast/color scheme for the calibration adjustable in a future version.
Best regards
Patrik