How to find a rainbow

Reena hates rainy days. She hates the way the dark clouds make everything look so dull.Rekha loves rainy days. She loves the way the rain makes the earth smell. When Rekha spots a rainbow, she rushes indoors to tell her sister about it. Reena will want to paint it, for sure! But when the sisters go outside to find it, the rainbow disappears. Where could it have gone?