obmmBrownBox

5 years later and this thread is the first Google result, with the jackass answer "LOL Google it". Lesson: get off your high horse and answer these types of questions. For anyone else trying to find the answer: Brown squares mean that the OMOD will overwrite a file, but the file is the same as the OMOD's version (CRCs match). I imagine this is the same for Morrowind Mod Manager (which is what I was searching for when I was brought here).