Darkening wheels

I know this may sound foolish but I am wondering if any of you skilled skinners can help me. I am trying to darken the color of the wheels on the Asobo 787 and 747. I edited what I thought was the correct dds file in the official texture folder but when loaded in the game it still looks the same. Has anyone tried to do this before? To me the wheels and rim textures just look to new. Any idea what file I need to modify or how to accomplish this?. Is it a decal I need to change?

Help!
Thanks in advance
Kevin

Topic moved into #sdk-discussion:aircraft