A person who identifies as pansexual does not see their attraction as something limited by a specific gender or genders. Its flag dates back roughly to 2010, and is meant to be distinct from the bisexual flag.
Per UNCO, the pink represents "attraction to those who identify as female," the blue "attraction to those who identify as male," and the yellow symbolizes "attraction to those who identify as genderqueer, nonbinary, agender, androgynous, or anyone who doesn’t identify on the male-female binary."