The secondary color of a part (individually or in an assembly) is showing up in my eDrawing files, 3D pdf and 3DVia files instead of the primary color. Anyone know why?

Not all my parts even have a secondary color option; they show up as intended. Obviously I’m not real well versed in working with appearances so bare with me. Why do some parts have secondary colors and other not? Is this a setting I can change somewhere so as to only have one color? The area I’m referring to here is the area right beside the eye dropper under ‘color’ when you RMB on a part or surface and click the Appearances ball then one of the icons that pop up. Some files have one place to set a color and some have two.