There seems to be something wrong with the VertexColors when using tubes.
dat = Table[{Cos[x], Sin[x], x/10}, {x, 0., 10}];
col = RGBColor /@ dat
{
Graphics3D[{PointSize[Large], Point[dat, VertexColors -> col],
Line[dat]}],
Graphics3D[{Thick, Line[dat, VertexColors -> col]}],
Graphics3D[{CapForm["Square"], JoinForm["Miter"],
Tube[dat, VertexColors -> col]}, Lighting -> "Neutral"]
}
This also seems to be the case in the documentation, this is an example from the VertexColors doc.
other examples in also fail like this one in the Tube doc.
