You wouldn't be able to tell by looking at the box or the cigars as the Anejo No. 77 Sharks all look alike. They're all in cello and have the red ribbon on the foot. These were first released in 2001 however the other Anejo sizes were first released in 2000 (the 46, 48, 49, 50 & 55). The original released Anejos have the "white" Fuente band but they didn't have the cedar wraps... all subsequent releases of Anejos have cedar on them but in the case of the Sharks... they have never had cedar on them at all.
The only way you might be able to determine the age of the Sharks would be by the degree of yellow on the cello but even that wouldn't be reliable. You'd probably have to trust your source and hope that they're honest. As for the original release Sharks being "dark"... it's a moot point as original released Sharks and subsequent releases of Sharks run the gamut of shades of darkness in the maduro wrappers.
Aloha,
Wade