Answered by Shaykh Faraz Rabbani
Are men allowed to wear red color clothing when they pray?
Walaikum assalam wa rahmatullah,
There are three colors that are best for men to avoid, in general (whether in our out of prayer):
and Pure yellow, when any of these colors is on its own without other colors.
It is not sinful to wear them, but it is somewhat disliked according to most scholars of the Hanafi school. [Ibn Abidin, Radd al-Muhtar, 5.228, Bulaq ed.]
And Allah alone gives success.