During the seven clean days, the layer of clothing that is closest to your skin should be white. If you prefer not to wear underwear while you are sleeping, you should wear white pajama pants or a white nightgown. If you wear just a white nightgown (or if you are not wearing anything), then you should sleep on white sheets.
If you wear white underwear or pants to sleep, then you may sleep on colored sheets (although some women still have the custom to use white sheets).
Please feel free to get back to us with any further questions.