In the beginning, a Stealthed were will still be partially visible, and can only hide themselves in shadows that are as large or larger than their bodies. But as they gain more power and control with training and time, they gain the ability to hide completely, seemingly invisible, even in smaller shadows than their own body, and some may even be able to mask their own scent.
Stealthed weres must not get overconfident in their abilities, and they must remember that the world does not rely only on sight. Even though they are harder to see, they still can be smelled unless they mask their scent, and they can always be heard if they are not careful.
A Stealth werewolf's best advantages are the arts of surprise and stealth, not their natural abilities. Nine-tenths of stealth is keeping your enemy from knowing you were ever there.