There's not a delicate way to ask this, so....
Tom,
As long as your peeing at least 4 cups a day, you shouldn't worry. (as long as there is no burning) Depending on what multivitamins your taking they can cause your urine to be many different colors. (bright yellow, tinge of neon yellow green, orange, brownish orange)
Tom I asked this same questions years ago when my doctor started having me take a multivitamin supplement. My doctor even told me it can cause it to have a different odor. Not that I ever went and smelled my urine.
--Sabrina