Don't worry about the big size.
Simplice resize the object how u want and consider that the plane surface is 50% of the total so for example u can resize to 100x20x4 and u can print from 0 to 2 mm with black and from 2 to 4 with yellow.
U can print with the same colour too, of course.
vr46.stl | 387.5KB |