Not sure, this may have other side effects, but I tried using a Within Budget 2:
IF [Budget Color Bar]>0
THEN SUM([Actual])-[Budget Color Bar]
and then fixed that starting of the axis at zero.
209621Budget Vs Actual.twbx 116.8 KB
This worked very well! I was able to avoid using the Axis start value being fixed to Zero by changing the calculation for the "Actual(-)" to subtract the Budget Color Bar value. This way it automatically terminates at Zero.
Thank you very much for the help!