* Disable lighting, which affects rendering tests in non-obvious ways.

* Show that the texture is explicitly never set in ddraw7.

* Show that the diffuse color is rendered in ddraw4 and ddraw7, which is
  consistent with the texture being unset in ddraw7 and suggests that the same
  applies to ddraw4.

This may or may not help with bug 54069, but if it does not, it hopefully will
at least make the reason for failure clearer.