All colour in wines comes from the skins being in contact with the juice, so you’re right about red wine coming from red grapes. And you’re also right about white wines can be made from white and red grapes, all they do is separate the skins from the juice as soon as possible. Rose wines are made the same way as red wine but with a shorter contact period of the skins to the juice. There is an exception to this and that is Rose Champagne. Rose champagne is a blend of red and white wine. This is a simplified explanation and if you would like more indepth details then you can check out wiki and search ‘Wine making’.
References :
Chef Sommelier. Run a team of Sommeliers.

Comment by Richard M on June 19, 2010 at 2:26 pm

Winemaking, or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from other fruit or non-toxic plant material. Mead is a wine that is made with honey being the primary ingredient after water.

Winemaking can be divided into two general categories: still wine production (without carbonation) and sparkling wine production (with carbonation). After the harvest, the grapes are crushed and allowed to ferment.

Red wine is made from the must (pulp) of red or black grapes that undergo fermentation together with the grape skins, while white wine is usually made by fermenting juice pressed from white grapes, but can also be made from must extracted from red grapes with minimal contact with the grapes’ skins. Rosé wines are made from red grapes where the juice is allowed to stay in contact with the dark skins long enough to pick up a pinkish color, but little of the tannins contained in the skins.

Most red wines derive their color from grape skins (the exception being varieties or hybrids of non-vinifera vines which contain juice pigmented with the dark Malvidin 3,5-diglucoside anthocyanin) and therefore contact between the juice and skins is essential for color extraction. Red wines are produced by destemming and crushing the grapes into a tank and leaving the skins in contact with the juice throughout the fermentation (maceration). It is possible to produce white (colorless) wines from red grapes by the fastidious pressing of uncrushed fruit. This minimizes contact between grape juice and skins (as in the making of Blanc de noirs sparkling wine, which is derived from Pinot noir, a red vinifera grape.)

Most white wines are processed without destemming or crushing and are transferred from picking bins directly to the press. This is to avoid any extraction of tannin from either the skins or grapeseeds, as well as maintaining proper juice flow through a matrix of grape clusters rather than loose berries. In some circumstances winemakers choose to crush white grapes for a short period of skin contact, usually for three to 24 hours. This serves to extract flavor and tannin from the skins (the tannin being extracted to encourage protein precipitation without excessive Bentonite addition) as well as Potassium ions, which participate in bitartrate precipitation (cream of tartar). It also results in an increase in the pH of the juice which may be desirable for overly acidic grapes. This was a practice more common in the 1970s than today, though still practiced by some Sauvignon blanc and Chardonnay producers in California.

In the case of rosé wines, the fruit is crushed and the dark skins are left in contact with the juice just long enough to extract the color that the winemaker desires. The must is then pressed, and fermentation continues as if the wine maker was making a white wine.

Have a look at the link, very interesting
References :
http://en.wikipedia.org/wiki/Winemaking

Comment by Les on June 19, 2010 at 3:00 pm

You are correct.

You can make red, white or rose wine from red skinned grapes, but only white from green skinned.

Basically all grapes are pressed with the skins on.

For white wine the juice is strained from skins/pips immediately, for red the juice is let stand on the skins/pips during fermentation.

Rose can be made in two ways;

Either mix red & white (the method used by most cheap rose manufacturers) – or by limiting the amount of time the juice is left on the skins – the longer they are on the skins the darker the wine will be, and the more tannins it will contain.
References :

Comment by Weatherman on June 19, 2010 at 3:12 pm

Rosé does come from red grapes. during the fermentation process, the grape skins are left in the vat for a short period of time, which gives rosés their pinkish colours. The more time the skin is left in, the more intense the colour.
The only white wine that I know that is made from red grapes is Chamagne. A blanc de noir Champagne is made from pinot noir grapes. The skins have been left in the vats for a very short period of time lending the wine the faintest of blushes.
References :

Comment by Sacha on June 19, 2010 at 3:29 pm

White wines can be made from Red or White Grapes but only the Juice or ‘Must’ as it is called, of the crushed grapes are used. Red wine is made using only Red grapes and it is the result of fermented Grape Juice and the Skins of the grapes (occasionally white grapes are used in small quantities to add complexity to the flavour). The longer the grape skins are kept in contact with the juice the more colour will come through. Rosé wine is usually made from Red grapes but the skins are only kept in contact with the juice for a short time. Occasionally on the cheaper end of the scale, red and white wines are mixed together but this does not usually produce wines of good quality and most suppliers in the Uk steer well clear of these.
References :
Cellarmaster at a 5 star Hotel with an Advanced Certificate in Wines and Spirits Educational Trust

Comment by haitchy0 on June 19, 2010 at 3:41 pm