Why doesnt "Chromatic Sword" have rainblow glow?

http://www.wowhead.com/item=1604/chromatic-sword

It was added in patch 1.11, its usually used as fun item to show off
On screenshots it shows a unique glow effect.
On Outland realm it doesnt have this effect just a normal sword.

Maybe the glow effect was added in wotlk or some later patch? Or is it a bug it doesnt show?

Thanks:)

The glow was added later on, I think in early wotlk, but you can see mentions of the change in various comments on wowhead and other databases. Here's an example.