Does your skin colour change significantly in different seasons?
If you are looking for your winter to summer (of summer to winter) skin tones here is a quick reference guide for foundation colours.
Pink Undertone
Midrange (Neutral) Undertone
Peach/Apricot Undertone
Warm/ Yellow Skin Tone
Mediterranean/Rich Yellow & Olive Undertone
Dark Caucasian, Asian and South Asian/Oceanic Skin Tone
African Warm and Cool Tones