The following answer contains an example that shows how to draw 3D surfaces with different colors. Not sure if this is what you are looking for:
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=5065000000080000008F250000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0
The following webpages may also provide some insight:
http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/e09eb9c864a320cd862568890005b388?OpenDocument
You can think of the x,y,z inputs to a 3D Parametric Graph as a 2D array of 3D vectors. For example, x(3,2), y(3,2), z(3,2) is equivalent to the 3D vector in space.