I was just reading over a site on a bit of Norse belief and found this at the end.
This is when one crosses the rainbow bridge from Midgard(Earth) to Asgard (relm of the Gods). This can is so clearly in conjunction with reaching GodHood and comeing that of the Gods.
The site: http://www.crossroads.wild.net.au/lependu.htm
Heimdall is the Gaurdian of Bifrost, the Rainbow Bridge
Heimdall: "Come, cross the Rainbow Bridge, Bifrost.
Cross from you Midgard realm of mortals, to the realm of the divine,
To do so you must raise the Serpent through the Rainbows in your spines
Through ssseven-coloured ssspectrum, ssseven chakras round which the Kundalini Ssserpent winds,
The Rainbow Ssserpent's ssshimmering ssscales are the ssseven notes, ssseven tones to ssset Her on Her climb...
