According to the Citizen Media Law Project, a website that says it is all about researching cyberspace, sharing in its study, and helping to pioneer its development, T-Mobile has recently sent a letter to Engadget to request that they stop using the color magenta in their logo on their Weblogs, Inc. hosted web page.
While this may seem trite, the letter from T-Mobile clearly, and as the website points out, politely says that the logo of T-Mobile is known worldwide, specifically in the United States and in the United Kingdom.
The two logos use the same color magenta to identify itself to the world.

Source: Deutsche Telekom / T-Mobile demands Engadget Mobile discontinue using the color magenta
The T-Mobile letter is also available on their website. The letter explains how they have marketed their look and how customers may get confused by the similarity of the logos. The letter further details how consumers may get confused about the sponsorship of the web page. With respect the consumer, the closeness of the logos may give the false impression that T-Mobile sponsors the web page, or vice-versa, creating a conflict of interest for those people who go to Engadget to check out the latest in mobile technology.
Many people I’ve spoken with do research prior to purchasing a phone. Jevaunda Bond, a T-Mobile customer says, “Before I bought the T-Mobile SDA, I spent two months researching the phone. I checked the T-Mobile website, CNet.com, and other community board type websites.” I showed her the two logos and ask her opinion on the situation and her response was, “A color is a color, but when you look at [the Engadget logo] and you realize the website is all about mobile technology, you are drawn to think it is somehow affiliated with T-Mobile. We are in a logo-heavy world…look at Coca-Cola. They are recognized world wide, of course if a soft drink consumer board came out with a similar logo, of course Coca-Cola would have a problem.”
If you visit Engadget today, you will see they backed down to T-Mobile, to the dismay of some fans of the website. But to operate a fair and balance marketplace you must not be or create the impression that you are affiliated in anyway with a company that you might praise or denounce.