In the systematic wine tasting method, observing the color of the wine is an indispensable step. Most of the defective wines are dark in color, with at least a hint of brown. It should be noted that some wines that are in good condition but have been aged for a period of time will also appear brown, especially those that have been aged in oak barrels for a long time. Secondly, the color of the wine can roughly reflect the age of the wine. As the wine ages, the color of red wine will gradually become lighter, from the initial purple to ruby red, and then to garnet red, while the color of white wine will become darker and darker, from lemon yellow to golden yellow, and finally to amber. By looking at the color, drinkers can initially judge whether there are defects in the wine. Furthermore, the darker the color of the wine, the fuller and heavier the wine is. In the case of white wine, we can also tell whether it has been aged in oak barrels by the depth of its color. For example, light yellow Chardonnay wines are generally not aged in oak barrels, while golden Chardonnay wines are mostly aged in oak barrels. In addition, the color transparency of wine that is not filtered before bottling will be low.