It doesn't matter, it's in the past
In the old days (pre 2011 code adoption), the NEC did not specifiy the insulation color of the wires in a circuit like this. The only applicable code would have been (200.7(C)), which said that the normally grounded conductor had to be reidentified using approved means. So either white or black could be used for either, as long as the white was reidentified as an ungrounded conductor.
According to the 2011 code...
National Electrical Code 2011
ARTICLE 404 Switches
404.2 Switch Connections.
(C) Switches Controlling Lighting Loads. Where switches control lighting loads supplied by a grounded general purpose branch circuit, a grounded circuit conductor shall be provided at the switch location.
A grounded (neutral) conductor is now required at each switch location (see code for exceptions), which means the circuit would now have to look like this...