I don't think it matters. I have swapped parts around in a few ballistics when I was being cheap and just bought a different turn stator. The color in the timing part of the motor seemed to match the same color as the stator. For example the Novak 17.5 motor I bought had yellow inside the timing end to match the yellow of the stator. I turned that motor into a 25.5 Ballistic and didn't have any issues.
I'm currently racing VTA. Check here for rules/info: http://www.usvintagetransam.com/