If the wings are directly from the fridge, let them sit on the counter for a half hour before deep frying them. Also, follow the suggestions others have had and make sure that you do them in small batches. The worst thing you can do when deep frying is to overload it. The oil temperature will drop when you add any amount of food, too much food will cause it to drop too low to create good browning and your deep fryer may not be able to compensate for it fast enough.
What I would do is to cook the wings once through until they are almost done, then crank the heat up to 375* or as high as the oil can take without smoking. Add the partially cooked wings back to the oil to crisp the outside, this time through the temperature drop will be much less dramatic and you may get better browning.
I can't comment on how well this works for wings, but this is the only way I have found to consistently make great french fries (fluffy and moist in the middle, crisp on the outside).
One more thing: I would get a fry thermometer and use it to make sure that you deep fryer is reading the correct temperature. It is possible that even with setting it at 350-375 it could be much lower, the only way you would know is with a thermometer.