I have been on a low-carb diet for two weeks and the last few days my urine has been tea colored instead of yellow. Should I be worried?

Not the diet. It is not likely that the diet is causing the changes in urine color, unless it's a fixed diet. Any reason to believe you got dehydrated? What do you do for fun? Any possible intense exercise lately? Taking any new supplements? Have you ever passed a kidney stone? Any other symptoms, burning, abdominal pain, fever?