They go through so many color changes from hatchling to adult. Some can be very lightly colored, and then change to blue. And they can continue to color until maturity, which does not happen until 2 1/2 - 3years old. You usually notice different colors, or brighter, after shedding occurs. Some of mine have shed about three times or more just over the spring and summer. So I have seen alot of changes going on. I congratulate you on your new buddy, I dont know waht color Sam was, but it's very normal to change, even darker, Yes. Post a pic when you get a chance let us meet Sam !
Eve