lighted, multi-colored polys

[Don Sosoka <eagle!monet.lerc.nasa.gov!xxdon;at;ucbvax.berkeley.edu>]

I know this should be an easy one and the answer must be docummented some-
 where but I can't find it.  Please Help!
 I want to draw smooth (GOURAUD) shaded lighted polygons starting with
 different colors at each vertex.  Assuming the lighting model is setup
 correct (which it seems to be), if I do something like
       call SHADEM (GOURAU)
       call BGNPOL
       do 10 i = 1,N
          vn(1) = XN(i)
          vn(2) = YN(i)
          vn(3) = ZN(i)
          call N3F (vn)
          icv(1) = IRED(i)
          icv(2) = IGREEN(i)
          icv(3) = IBLUE(i)
          call C3I (icv)
          v(1) = X(i)
          v(2) = Y(i)
          v(3) = Z(i)
          call V3F (v)
 10    continue
       call ENDPOL
 I get smooth shaded colored polygons but no lighting effects.  If I reverse the
 order:
       call SHADEM (GOURAU)
       call BGNPOL
       do 10 i = 1,N
          icv(1) = IRED(i)
          icv(2) = IGREEN(i)
          icv(3) = IBLUE(i)
          call C3I (icv)
          vn(1) = XN(i)
          vn(2) = YN(i)
          vn(3) = ZN(i)
          call N3F (vn)
          v(1) = X(i)
          v(2) = Y(i)
          v(3) = Z(i)
          call V3F (v)
 10    continue
       call ENDPOL
 I get a nicely lit surface but all gray shaded.
 What's the trick? (or am I way off base).
 Thank's.