Sometimes Gecko color fades with the passage of time when it ages to maturity but it depends on the fact that which breed you have in your home. In your case there seems some problem because it is also jumping that is unusual and seems abnormal to you. So it is much better that you take it to vet for its thorough check to know that cause. It seems that it is not shedding but suffering from some disease. Note other symptoms as well before going to vet.