The ShapeAppearance is a list of materials and thus assigning a color with 'obj.ViewObject.ShapeAppearance.DiffuseColor = color'
is incorrect.
But doing it with 'obj.ViewObject.ShapeAppearance[0].DiffuseColor = color' doesn't work as expected because the
internal notification doesn't work with a list.
So, the only viable way is to revert the changes and do it by assigning the color to the 'ShapeColor' attribute.
Uses new material system for appearance
Each feature object now has a property called ShapeMaterial that
describes its physical properties. If it has a shape, it has a
material.
The ShapeColor attribute is replaced by a ShapeAppearance attribute.
This is a material list that describes all appearance properties, not
just diffuse color. As a list in can be used for all elements of a
shape, such as edges and faces.
A new widget is provided to allow the user to select materials in a
consistent fashion. It can also launch the material editor with its
more advanced capabilities.
