Is it permissible for a man to sell women's underwear, taking into account that he asks the woman about the color and size, and advises her on a specific type, saying that it suits her skin tone?

There is no harm in a man selling women's underwear, provided he adheres to Islamic regulations, such as avoiding khalwah (private seclusion) and physical contact, and that the woman observes hijab (definition) and modesty when making the purchase. It is preferable for a woman to sell these garments. There is no harm in a man asking about the color and size, but he should not say, "This type suits your skin tone," as this is from the steps of Satan.