Like it or not, the first quality of a wine that lends itself to the taster is the visual clue given by the appearance of the wine in the glass. To appreciate the true colors in the wine you must tilt the wine at an angle of about forty degrees and hold it against a white background, this environment lends itself to viewing the wine in the best of circumstances. This initial stimulus sometimes hints at a clue as to what the wine will taste like or perhaps more probably what it will not taste like. A deep red color in the glass may well borrow its likeness to a quality grape, even to circuit professionals and the most ardent of tasters. Caution is advised though because while, hints may be given as to the quality of the wine, do not pay too much credence to the color (even the best have been fooled by this).
Look at the clarity of the wine, it should be brilliantly clear without debris or cloudiness. Debt is a technical term in tasting which describes the balance between the clarity and haziness of the wine. Bottled wine must be carefully poured in order to separate the wine from the sediment in the bottle which could in turn lead to the wine turning to debt.
The depth of the color of the wine refers to the brightness of the color in the glass and the hue concentrates more on the actually shade or tint of the overall color. These two aspects give clue to the maturity of the grape and perhaps the age of the wine. A young and immature wine will have little color compared to an over matured wine which will give a dense and yellow colored wine. Mature red wines will often have an incredible lush red with a fantastic hue and tint. Wines, which borrow natural processes with oak casks, gain significance in color from the tannins in the cask this gain may be only temporary but will credit itself to an enhancement of the color depth.
There are many, many factors affecting the color of the wine and it is impracticable to be dogmatic about the significance of any particular hue or overall color. If you have some background knowledge of the grapes in a particular wine then it will be possible to make a judgment on the wine, it can for example show faults in a wine and give clues to imperfections in the process of making the wine of indeed in the storage of it.
Taking a careful look at the rim of the glass will give you a definite indication of the age of the wine. A dense purple edge will indicate a youthful wine while a darker almost black rim will give you the first sign of aging. It is very difficult to judge a wine from color alone and there is no real standard in all of this and it is not possible to credit any particular terms, as they are all observational and unique to each person.