Winter and Summer complexions are both cool skin tones with a blue base. These 'seasons' so to speak are helpful when determining what clothing to buy and what to wear.
Both of these seasons are best served by wearing cooler or more blue based colors.
Summers differ from winter complexions in that they are a bit softer. Winters will have a large contrast between their skin, hair and eyes where summers will bled more gently together. Because summers are themselves of softer tones, they look best in blended colors, not with dramatic variations. Wearing strong contrasted colors will make them appear overpowered and tired.
Winter complexions are usually more dramatic with a strong contrast between skin, hair and eyes. The combination of black hair, pale skin and blue eyes. is a typical indicator of a 'winter' complexion. A strong pairing of contrasting colors will enliven and accent the already intense look of a winter.
Taking notice of the colors in nature during each of these seasons also helps you determine which colors correspond with your tonality. Take for instance the stark contrast of crisp white winter snow and the deep red of a poinsettia.