Sparkgender is a gender identity where one is normally agender/genderless, but they sometimes experience "sparks" or "bursts" of a gender. When these "sparks" end they return to being agender/genderless. These "sparks" can be any gender or gender identity, and they don't always have to be the same.
Flag
The yellow and orange stripes represent the "sparks" of feeling a certain gender. The black in the middle represents feeling genderless most of the time.