What herb?

Dominican cuisine, especially the meat dishes, are heavily flavored with fresh OREGANO leaves. This herb imparts a strong flavor when used in larger proportions (2 tbsp+).

Saffron is a spice, not an herb and its flavor is delicate and almost floral.

Spices and Cooking

Spices are prominent in the islands and help to define regional cuisines. Onion and garlic are utilized throughout, with ginger, allspice, lime, cumin, cilantro, cloves, nutmeg, cinnamon, bay leaf, and a variety of hot peppers appearing throughout the more localized food offerings. Jamaican cooking particularly favors the potent Scotch Bonnet pepper, and uses it in its signature spice blend, jerk. Jerk is a combination of allspice, Scotch Bonnet peppers, garlic, cloves, and cinnamon or nutmeg, which is dry rubbed into meat before grilling or steaming in banana leaves. Puerto Rican and Cuban cooking by comparison are much milder, using spices to add flavor without heat, as in the case of Puerto Rican sofrito (a base sauce consisting of vegetables, herbs, spices, and sometimes tomato) and Cuban mojo or mojito (oil, onion, garlic, and lime juice).

It's most likely Saffron, an expensive herb in most places, but you can most likely find it any grocery with a good supply of different herbs.

what color was it? if it made you dishes red, it was probably saffron. but if it was green, it may have been cilantro.

saffron