Colour of Urine

I've just flared after being in remission for almost a year.  I've been back on prednisone (40mg) for almost 2 weeks and have noticed that the colour of my urine is much darker and brighther than normal even though I'm drinking lots of water.  Does anyone know why this might be happening?

I'm taking a multivitamin

I haven't noticed a really strong smell but it might be more of a smell than normal