It's sunburn. The leaves will look sort of silvery but don't wither. The leaves won't regain normal color--at least in my experience--but the plant will put out new ones that are adapted to the sun exposure.

HTH.

I never move my plants to full sun after a winter indoors. Some people slowly acclimate them to full sun over a period of weeks, but I find my plants actually do better in part sun (early morning best) with some shading in the afternoon. And I keep them there all summer. This keeps the potting soil from overheating and I think it minimizes the shock when bringing them indoors in the Fall as well. They still bloom and bear for me. Just my opinion.