I honestly don't know what you mean. I have almost no interest in copyright law as it is. All I know is that I believe that if I make a magenta cell phone and start selling it, T-Mobile might get upset. Please explain what you mean.
tl;dr: Trademarks are more to do with logos and branding, their intent being to allow a company to distinguish themselves in a market with a certain identity. Violations of Trademarks are usually linked to consumers being mislead into believing a product is from one company when it is in fact from another.
T-Mobile does not own a copyright for Magenta. They don't own Magenta. If I want to make Magenta chairs they have no say. They would never receive a Trademark on black, however.
If you start making magenta phones, it's reasonable to assume that the average consumer would confuse them with the already popular magenta phones being promoted by T-Mobile, and this might damage their brand, given that your phones might not work to the same standard.
It's generally not good to form an opinion of topics before you actually obtain a relevant amount of education. It can lead you to making yourself look really stupid.
It's a trademark, not a copyright. Trademarks are intended to protect consumers, not companies. Legally, it's only infringement if consumers might be confused. So I can say the word Facebook here, and as long as it's obvious that I'm not claiming to be Facebook, or diluting the brand, it's OK.
