You can learn a lot about wine from the colour. In red wines, if there are any purple hues in the wine, generally, this means the wine is young. If there are more brick red or orange hues in the spectrum, the wine may be older.
In white wines, a more golden yellow colour rather than pale light yellow could mean the wine is older, the wine has been in oak, or the wine is sweeter.
If the white or red wine is clear and bright in colour, rather than opaque and cloudy, this is a good sign that the wine is sound and clean.