Change Color of Boxes on LineZone Trigger

[iturner72]

I implemented the functionality have the color of the boxes change when it's crossed the counting line. My use case is strange and it would be helpful for the user to see this change.

I modified the annotate function in the BoxAnnotator class on my fork of the repo to accept an optional list of tuples called custom_colors to achieve this.

Was my hacky solution necessary or is there a better way to do this with the existing release?