You asked if it could've been the Melanotan II ... from personal experience as well as from buddy's of mine who have ran it before, none of us ever experienced any increased redness solely from using MTII. I was using the tanning beds a lot while taking it, which only enhanced the darkening effects of the chem.
.. but I got too many random spots on my body to continue using MTII. I would've enjoyed another 60 day 'trial' with 40-60mg total, but too worried of these 'spots' popping up everywhere. I only ran 20mg consecutively last time around (2 yrs ago), for about 30 days total. MTII + tanning bed got me a lot more tan than tanning bed by itself.