hi, u could try a tighter crop to focus more on the subject, and increasing the contrast in ur pics, then the colors will look richer. composition wise, u could try to photograph more of their faces rather than their backs, keep both their faces in focus, and try to avoid distracting backgrounds like the fan behind the bride in the 2nd shot.
I think the first shot is a total miss. You need to back it up to include the arms of the groom and wait for them to have some interesting expression (eg easiest is smiling). Also, focus on the subject closest to you from this angle and if you wanna play with DOF. I think for prayer session, very little chance lar to take interesting expression lar.
#2, this would work if you included the whole altar and shot from a position which is perpendicular to the altar. Your position included the wall which makes it dull.
Both pics are quite underexposed. If you level it up, saturation would increase by default.
BTW, you could post in Reportage and Sports gallery in the future if you want critiques.