Why is Self Illumination not an option on certain appearances?

[drafting3QE6L]

I am fairly new to Inventor Studio and I am getting my bearings with lights and illumination. My problem is that certain appearances my company uses for lights, etc. do not have the "Self Illumination" option in the style editor. In this one case, appearance "Yellow" has the headings "Information", "Wall Paint", and "Tint" available in the editor, but appearance "Snow" has many more headings, including the desired "Self Illumination". Is Self Illumination simply not available for certain appearances?

[gcoombridge · Accepted solution]

Appearances are created in certain categories. To have self-illumination I think they need to belong to the broadest category - Generic. You may need to build a few comparable appearances to replace the existing ones for studio...