Why Your Pee Turns Bright Yellow from Certain Supplements What is glutathione and why must we protect patient access to it? What do your urine color says about your health? Clear urine is a sign of good hydration and potential overhydration. Pale yellow urine is an indicator of good hydration. Dark yellow urine Vitamin B supplements, especially those containing riboflavin (vitamin B2), often cause bright yellow or neon colored urine. This happens because excess riboflavin is water soluble and is excreted through urine when the body has