Is a garment considered transparent if it reveals the color of the undergarments but does not distinguish the color of the thigh or skin due to the light color of the garment and the skin color?

If the trousers do not reveal the skin color underneath, then prayer in them is permissible. If they are transparent, and a garment is worn over them that covers the awrah (from the navel to the knee for a man), then the prayer is valid.