The more blue or purple, the younger. CM wines are very purple. Orange or bricky denotes age. From red fruits to dark bramble fruit. Raspberry and cotton candy in CM wines.
Older wines tend to be lacking fruit.
When they are young they are the rough almost tactile sensation in the mouth. The harsh ones are from the seed and stems. The softer tannins are from oak. Leather flavors in aged red wine is are to be expected. TANnin is used to TAN leather, so the smell is from the tannins.