Red leaf edges
When you bring a succulent plant that was growing outside back inside in winter, it can become stressed as it gets used to a new environment. The same thing happens when it goes back outside in spring and has to change again. Many succulents, including the jade plant (Crassula ovata) shown here, react to this stress by turning red on their leaf edges and losing their green color.
Be patient, once the plant adapts to its new growing conditions, it will regain its green color. In spring, when you first take the plant back outside, put it in the shade for a couple of days, then move it gradually back out into full sun. After a week or two, the plant will acclimate to its new home and green up on its own.