Discolouration After pimples

Not until about last year did I experience nodular acne, and I was eventually started on 30 mg Accutane, which took care of my skin until about a month or two into the treatment then I experienced a continuous break out that lasted over a month and a half, and was atleast triple as bad of acne as I have ever had. Is it normal for thisto happen? I eventually went from a family doctor recently after 4 months on Accutane, and my Derm put me onto prednisone doxycyline to control things, within the week I've been taking this treatment my face has cleared up, but because of the daily pustules i was getting on accutane I have many many red/ purple Discoloration spots where old pimples were. How do I get rid of these? From first glance I look like I have a crazy amount of pimples but only have 3 at the moment. The spots seem to last for a very long time and I am getting sick of them,- also is it unusual that these discolourations have gotten much worse in the winter, and when I tan they leave completely? Should I consider tanning to even out the skin tone even though they say that I should be avoiding sun whilst on acne medications? ( I rarely burn with out sunscreen when not medicated)
My new Derm wants to put me onto accutane again at a higher dose and this is going into 5 months since the start of the accutane, that i will now have to be restarting, Do you think that will clear up the spots?
These splotchces are driving me crazy!
Thanks!