What is the red that is forbidden, what is the red that the Prophet (peace be upon him) wore, and what is the "mu'asfar" color?

The basic principle concerning clothing is that it is permissible to wear all colors, unless it involves imitating the opposite gender, or is a garment of fame (libās shuhra), or entails extravagance and pride, or is silk for men. It is permissible to wear all colors such as white, red, yellow, green, and striped, and there is no dislike (karāha) in that. The best of them is white. Some scholars have held the view that wearing red and saffron-dyed (mu‘asfar) clothes is disliked, but the more preponderant opinion (al-rājiḥ) is that wearing them is permissible. There is no harm in wearing the clothing of the country one resides in, or the clothing of one's original country, regardless of the color.