[periferral]

You are joking. All multimeters I've worked with have been yellow. And all multimeters look like ... em... multimeters.

https://www.google.com/search?q=multimeter&safe=active&sourc...

[caw]

The mark is for "contrasting yellow border". I can pick out the Fluke equipment easily from all those images.

It's not protecting the use of yellow, which is why the pure yellow devices exist.

[mikeash]

I clicked on ones with what I judged to be a "contrasting yellow border" and only about 50% of them were actually Flukes. Seems this trademark is not evenly enforced.