Can the scar fade some what after a tummy tuck?

Maybe. Scars will fade over time. It depends on how long ago your surgery was as to whether it will continue to fade.
Scars. do fade with time, but it takes about a year. If your incision is recent, there is a new breakthrough dressing, called "embrace", which can help the scar look it's best, if it is used early in the healing process. Otherwise, avoidance of sun on the scar, scar massage, and a silicone based scar product are the standard methods for optimizing healing.