I was just pointing out what my understanding of a trademark is and how I think it wouldn't apply for the Dell vs Macbook example.

In any case, I don't think I'm qualified to have an opinion in the case being discussed here. Both because my understanding of trademark law is just a very general sense of what it is supposed to stand for and because I have absolutely no notion of what are the multimeter brands out there and what their designs look like.

For what it's worth, all the multimeters I recall using at school were either all yellow or all black and I have the feeling they were always the same brand although I don't remember what that was (I studied in Europe)