Hi eric, that grey color happens because the object is shaded with the light source, so it's only at the brightest color where its surface normal is oriented towards the light, and gets darker when the surface normal is angled away from the light.

But you can get a full white appearance everywhere (essentially disabling shading) by turning up the light intensity to very high.

See this previous post for some explanation on how to do that:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3135.3

- Michael