Cannot Remove Color from a Subassembly

Hi,

I am using Solidworks Education Edition 2011-2012 / 2011 SP2.0.

I have a main assembly that is made of some parts and some other assemblies (sub-assemblies). It seems like a gray color is applied to one of those sub-assemblies (see img1, "Assem_OutterBox") and that overrides the colors of the individual parts of that sub-assembly.

If I open that sub-assembly on its own, there is no overriding color and each part has its own color (see img2). This is how I'd like to see it in the main assembly.

I tried to remove the overriding color (gray) by right clicking on the sub-assembly (Assem_OutterBox), choosing Appearances (beach ball) and finally clicking to the option "Remove Color" (see img3). However nothing happens and my sub-assembly stays gray. Playing with options in Appearances ("Apply at component level" and "Apply at part document level") doesn't seem to help, if anything I can set the override color (left-top half-triangle this time) but it doesn't affect the right-bottom half-triangle. Trying to clear overrides with "Clear Top level overrides" doesnt help either.

Other subassemblies that do not have the right-bottom half-triangle show part colors as they are defined in individual parts.

So the question is: how to remove the color (i.e., right-bottom half-triangle) from the top level sub-assembly?

SolidworksAssemblies