I just noticed that my newer VFR charts show the Class B Mode C veil 30
nm ring as a magenta line, the same color as used for Class C
boundaries. My (still unrecycled) older charts show it as a blue line.
When did change and does anyone know why? The blue line made it
clearer that it was associated with the blue airspace rings.

Also, N47 (Pottstown Muni, PA) now sits right on the mode C veil.
Previously it was charted well outside the veil. Was there a datum
change that moved an airport or the veil that much?