Gladiator camo patterns varied more than "normal" for RAF aircraft, and I think I've figured out why.  The Gladiator entered production before the Munich Crisis of 1938, which is when the RAF introduced dark earth/dark green camo, so most Gladiators were completed in over-all silver dope.  Consequently, most Gladiator camo was applied in depot or in the field - this would explain why there was so much variation in the camo patterns.  To make matters worse, the RAF introduced 4-color camo (for biplanes) just before the shooting started - this resulted in even more variation. 
  
So, the Mk 1 will have the initial 2-color pattern, and the Mk 2 will have the later 4-color pattern.  Photos show both patterns used wherever the Gladiator was deployed - Britain, France, Norway, Egypt, Sudan, etc. 
  
EDIT:  Per the Mushroom pub on the Gladiator (thanks Wrench!) many of the Gladiators sent to Norway had dark earth on the upper wings over-painted with medium gray, and sometimes dark earth on the lower wings was over-painted with sky gray.