What Causes Red Or Blue Hands When In Cold?

MY DAUGHTER SINCE SHE WAS LITTLE HAS ALWAYS HAD COLD HANDS..........SHE IS 17 NOW ABOUT 5'5 AND 105 LBS...............COLOR RED SOMETIMES DARK RED TO BLUE..............BUT THE REST OF HER IS OK AND SHE IS NOT COLD.............................SHE DOES NOT LIKE WARM, HOT WEATHER, SHE PREFERS COLD WEATHER