Should I or shouldn't I?

Sometimes there are things that work and sometimes they don't.   The problem is that technically, this works.  The problem is that it still might not mean it should work.

Sigh.  Questions, always questions.

I have loved Tempest, desinged by Ann Weaver, from Knitty.com.  I have worked at finding the right yarns.  I have played with different combinations, and different gauges as I worked through my stash, but could never decide.  

This is my latest sample.  The solid colour yarn is Filati Fine from Elann.  It is nice stuff, 45 % acrylic, 35% wool and 25% nylon.  Definitely a blend.  But a nice feeling one.

The multi colour is Fleece Aritst 2/8 BFL.  Not a blend but one of the finest yarns on the market.  Pure lovely soft Blue Faced Leicester. 100% wool.  A yarn to sigh over, and I do.  

Technically the colours work.  If you are trying to see if you have a good combination, take all the colour out of it and see.  I did and the tones are ok.  I think I like it.  But I liked the last sample I did for this sweater too yet I did not knit it.  I was just never sure.

My question here is, do you mix these two  very different yarns?  I am going to wash and block my sample.  Maybe that will help answer my question.