Red cabbage is cabbage that has a purplish or red colour on the outside leaves. Cross-sections of most varieties will reveal purplish and white layers inside.
Apart from colour, however, it tastes just like regular green cabbage. This means it is safe to use in coleslaws, etc, to jazz them up visually.
After your red cabbage is cooked, if it has lost its vibrant red colour and you want to restore that, then toss it in a tablespoonful or two to taste of lemon juice or vinegar. The acid will both enhance the taste and restore the colour. If you simmered the cabbage in water, drain it first.
Don’t leave red cabbage sitting on or in any china or porcelain dishes for more than a few hours, as its pigmentation may permanently stain the crockery blue where it was.
Be forewarned that when cooked with other food, its colour can leach out and colour that other food a bluish-purple. If you boil the cabbage, the water you boil it in will turn blue.