I have anthracite TTM's on my car, so I definitely like these too. Good choice!
As for whether or not they're Mustang rims? WRONG.
Torq-Thrusts have been manufactured by American Racing since 1957, years before the Mustang was even a twinkle in Ford's eye; and their original purpose was applied on the dragstrip, but it became a popular street racing wheel. The Torq Thrust was specifically designed with a "tapered parabolic contour" spoke, as opposed to a semi-solid modular design, to increase brake cooling and simultaneously decrease wheel mass. It is often considered the most famous muscle car wheel of all time and is sometimes credited as starting the entire custom wheel movement.
The reason people associate these wheels with Mustangs is because Bullitt wore them, and as a result; Ford went and modeled one of the 2005-2009 Mustang's stock wheel choices after them, exacerbating the first impression that they're Mustang wheels, even though they're not. Go to any classic hot rod show, and you'll see Torq-Thrusts adorning all kinds of makes and models (the Torq-Thrust II version is particularly common on 4th gen F-bodys). They're NOT a Mustang wheel, Ford copied American Racing - not the other way around, and most Camaro owners who run TTM's have to deal with this misconception ALL the time. It gets annoying.
In closing, those of you who like these wheels but don't want to deal with the reputation - screw them, and just tell any haters what you just heard in this post. Get your Torq-Thrusts!