MWLite.Symbology.dll is a .NET assembly, and generally can't be used in VBA. There is a workaround through registering it as ActiveX control, though I don't know if it's practical. To display color categories in VBA I'd rather search for some available grid-like ActiveX control, which supports custom drawing and write the code myself.
Hope it helps,
Sergei
Hope it helps,
Sergei