"WOLFEN NP100 differs from WOLFEN UN54 in that it has an additional dyed antihalation layer. This layer is positioned between the base material and the emulsion layer and has the task of preventing the formation of a reflection halo. This improves image sharpness."
This may be the only difference, and it could be significant.
Spectral response of NP100 is very different from that of UN54 going by the datasheet.
) whether the dyed anti-halation layer may not cause that shift by absorbing some reflected light (maybe B). But given its position under the emulsion, it may be too late to have much if any effect.

