Just to touch on the protein suggestion earlier,,, I take in a lot of protein (150-200g a day) as I am the Gym a lot and training for the North run right now. It can make a change to urine colour and I have even heard from lads on one of the fitness forums reporting it makes his foamy,,, usually with myself it will be darker right after a protein shake,,but more of a really strong yellow than tea,, but then everybody's different. Also any sudden changes to lifestyle and diet could also be a cause, I wouldn't worry but I would mention it nest time you see the GP or take in a sample.