Phase relationships in 2-color 3x2 Z's

There are two possible phase relationships in twining three 2-color, 2-plies into a 3-ply:

Color phase relationship in a 3x2 compound helix where the nearly axial rows are 1B1W.

Color phase relationship where the nearly axial rows are 3B3W.

When the first two 2-plies are twined, they can be screwed past each other into configurations that (in the direction parallel to the axis) pair either BB and WW, or BW and WB. The latter pairing leads to the 1B1W phase relationship if the third 2-ply is phased to continue the WBWB alternation. Any other color phasing of the 2-plies results in the 3B3W phase relationship.