I second white/gray for the younglings' 'training sabers'

However, in my dream edit, the younglings scene would never appear anyway.

I love the idea of all the Prequel sabers being blue, that way, in ROTJ when luke fires up his new one, it's a ZOMGWTF moment.

Hints that he could be straying from the 'proper' jedi path, and signifies a new era.

The only possible exception would be dooku (if someone does an edit where he's not a sith) perhaps his could be green too, or another colour even. Orange? Yellow? I'm sick of purple simply due to Sam Jackson.