Hi,
Sage does not have seed pods. The seeds ripen in the calyxes. The calyxes are the little cup type things that the flowers grew out of. Salvia seeds are usually ripe when the calyx turns brown or grey/get dry. The seeds can be black to grey and round or oval depending on the type of sage. If they are green or white, they are not ripe yet. Depending on the type of salvia, there can be one to a few seeds in a calyx. Some salvias hold onto their seeds for a long time and are easy to collect seed from. Some types let them drop right away and are obvious more difficult to get seed from.
Hope that helps,
Remy