Currently there is not an easy way to adjust shaded color views in Inventor's drawing environment. Shaded Drawing views currently use a lighting style not available to users to edit. The addition of the specular color toggle was a nice improvement but there needs to be a setting to completely disable lighting if a user chooses to. This could then provide a simple color for an entire part instead of one that presents shadows and gradients.
Purposed solution;
Add an additional toggle to drawing view dialogs or document settings for "Simple Shaded View and "Advanced Shaded View" where one presents the colors simply as they are with no highlighting or shadows and another option for as it currently is in the software. Other CAD programs can do this and while it is a cosmetic issue that does not affect all users, some users rely on color in their views.