It is important that succulents are placed in indirect sunlight. If you have to keep your succulent indoors make sure that the plant gets adequate light. The sap can cause skin irritation. Your succulent can turn yellow from overwatering or underwatering. The most common cause of a succulent turning yellow is too much water. The scorching sun may cause your succulent to become yellowed if it is not stored in the afternoon. Don't water your Sempervivum for several days after repotting. Before you repot it, let it dry completely.