If you already know the wine, the color can tell you a lot about its “fitness” or “correctness.”
Look at the wine and its color. Is it clear or cloudy? Transparent or opaque? If you can, hold the wine glass against a white surface like a napkin or table cloth (this is the best way to see the color and opacity/transparency of the wine). If you already know the wine, the color can tell you a lot about its “fitness” or “correctness.”