What colours does the state flag of Hesse have?

EDITORIAL LEARNING AID

Why is this answer correct?

The state flag of Hesse is red and white. Blue-white-red, black-gold and green-white-red are not Hessian state colours.

Hesse: red-white, like the lion in the coat of arms.

This translation and explanation are editorial learning aids. The official German wording and answer key govern the examination.