If you are vegan, how is it possible for urine to still be yellow if you are only consuming greens, not meat(urea)?

Urochrome: The yellow color in your urine -- whether carnivore or vegan -- is due to a pigment called urochrome. The color varies from pale yellow to deep amber, depending on how concentrated it is. If very dark, you're likely dehydrated. Vitamins (especially b's like riboflavin) can color it very yellow. Some meds can turn it blue or green. If it's red, see your doctor to check for bleeding.

Urine Color: The urine is still probably yellow because you are not drinking enough water.. Being well-hydrated often leads to a much clearer urine.