How can you tell the difference?

[DennisM]

The axanthic pied will be obvious, they will be lightning pied. All others will be ordinary looking pieds, on average 2/3 of these will be het for axanthic. However, you won't be able to visually tell the axanthic hets from the non hets.

this answer only applies if the axanthic lines are compatible. I'm not sure what the current state of compatibility is as I don't keep axanthics.