PIE for rainbow?

From: Joao S. Lopes
Message: 66443
Date: 2010-08-13

Is there any PIE word for "rainbow" ? Any common mythological trait for PIE
religion? In Scandinavia, Bifro¨st was the bridge between Midgard and Asgard; in
India was the bow of Indra; in Greece, Iris was the messenger of goddess Hera.

JS Lopes