The color of urine when the body burns fat depends on many things. Generally, it will be a pale yellow color, but it can range from almost clear to a darker yellow or even brown. Urine is mostly water, so its color will depend on how much water the body has had, the presence of certain vitamins and minerals, and whether or not the body is burning fat. Certain foods, medicines, and other substances can also affect the color of the urine. In some cases, the color of the urine can also be a sign of an underlying medical condition. Therefore, it is important to consult with a doctor if there is any concern about the color of the urine.