What is the ruling on a man wearing red and yellow garments? Does the ruling differ if they are of a single color or intermingled? And what is the ruling on a girl wearing such garments?

The basic principle is the permissibility of wearing all types of clothes for men and women, whether in a single color or multiple colors, as long as there is no imitation of one gender by the other, or if it is not a garment of fame, or involves extravagance and pride, or if it is silk for men. The evidence for this is the saying of the Prophet, peace be upon him: "Eat, drink, give Sadaqah, and wear clothes without extravagance or pride." The preponderant opinion is the permissibility of wearing red and safflower-dyed clothes, unless there is an external impediment, and this is because it is narrated in the Sahihayn that the Prophet, peace be upon him, wore a red Hullah (suit/garment).