A question about urine

Could possibly be you've not enough fluids on board - I'm quite often like this when I wake in the morning if I haven't had a drink close to going to bed.

Dark yellow is usually a sign of not enough fluids. If it is a dark brown colour, I would recommend talking to your GP.

Mine is often brownish but in fairness I do have a bladder issue due to long term T1

A change in your urine colour is normally due to something completely normal, but just occasionally it may be a sign that you should seek medical advice.

Urine gets it colour from the pigment urochrome and the colour normally ranges between light yellow and dark amber. The darker the colour of the urine, the more concentrated it will be. Because people tend to sleep for several hours without having a drink, their urine is normally darker when urinating first thing in the morning.

Darker urine during the day or evening can indicate dehydration, meaning you're not drinking enough fluids. Drinking lots of fluids will make urine lighter. However, taking a diuretic, a medication to get rid of excess water in the body, also makes urine turn pale, as does diabetes insipidus, a rare type of diabetes.

You may notice that when eating certain foods such as beetroot the colour of your urine changes - though this doesn't happen in everyone. Taking certain medications can also make the colour of urine change. Vitamin supplements may change the urine to a particularly bright colour. These changes, which are harmless, are due to the pigments and compounds in the food, supplements or medication. How much the colour of your urine changes will depend on how much food you eat or supplements or medication you take, how hydrated you are and on your own body chemistry.
http://www.webmd.boots.com/urinary-incontinence/urine-colour-changes