The colour of red wines is derived from the pigments found in the grape skins, the flesh of the grape does not affect the colour of red wines. The colour of the wine depends upon the method of vinification and the time the must is in contact with the skins.
Some varieties such as Syrah and Cabernet Sauvignon provide significant pigment colour to the must during fermentation whilst others such as Pinot Noir and Grenache offer less pigment colour.
The colour of a few wines is affected by the colour of the flesh. The are called teinturier varieties, these have red skins and red pigmented flesh. There are very few Teinturier varieties, examples include Alicante Bouschet, Sepevani, Dunkelfelder, Garnacha Tintorea, Pinot Teinturier, Rubired and Sulmer.
The ageing process of some red wines, ensures a change in colour. From young wines with dark purple colour they change to a ruby red colour. Continuous ageing will progress the colour change until they become light red or even brown red – probably undrinkable!.