Urine colour comes mostly from the breakdown of:

1. The pigment traces back to haemoglobin. 2. The liver converts heme for excretion. 3. The color of urine is determined mostly by the breakdown products of red blood cell destruction. 4. So the answer is red blood cells. _Source: OpenStax 'Anatomy and Physiology 2e', Ch 25 'The Urinary System'_