Yeah I agree with this. It isn't that I don't like yellow, but I don't like too much yellow. I think DHL's scheme of all yellow with some specks of red is horrific. But on the other hand, you cannot mistake a vehicle or worker of theirs for something else, and you can spot a DHL van or truck from a mile away. I think Sprint's new scheme is pretty bad too. I like their new logo design better, but they've got way too much yellow going on.
Oh but let's not forget Google. They've got all the primary colors + yellow in theirs. [I don't mind the yellow here]
Though, it would be interesting to see what percentage of the Fortune 500 companies use some combination of red, blue, black [and white]. I checked the top 10 and all of them do, several using blue & red [& white].
edit just checked top 20, and all but a couple use some combo of those colors. Altria (#20) being the most rebellious of the pack.
It would also be interesting to see the common colors of corporations from different areas of the world. It is quite possible that culture plays an important role too.