All you need to look at is the number of years between creation of a Sun Sphere on the Sun and the number of years the Sun Atlamillia can travel, either direction, through time. They're both 10,000 years. Caught in the evil Dark Cloud below Dark Heaven Castle, the Sun Sphere absorbed the evil energy, losing its green stripes and became pure yellow. Like the "lucky" rat, the Sun Sphere absorbed some of the Dark Genie's power.