It's also sold here!
http://www.reflexracing.net/GRC402-G...id_p_1713.html
I've been running Blue front and Black rears with my gear diff lately too. Except I run a high front diff and low rear. Hopefully I'll have my Black Edition here before the weekend and I can test it out.
I did notice other Yokomo setups that run a softer spring up front than the rear. Looks to be something to try when nothing else seems to work. I'd like to know what they DID try that didn't work for this situation.