T-Mobile is the proud owner of a trademark which says it owns the colour Magenta. T-Mobile and its parent Deutsche Telekom, have trademarked magenta.
The move means that if you are painting a picture you should be ok using the Magenta tube but if you are thinking about it in connection with anything telephonish you can expect a visit from T-Mobile's lawyers. Actually it probably also applies to the Interweb so any designs using Magenta should be deleted right away. When you look at a Magenta sunset, the trademark implies, you immediately think of T-Mobile's phone services.
Have to go now... register myself some RGB