Just an "idea" here...I personally would use two of those different colors side by side. I would also try staggering them as they are space dyed.If you read the article in Rodmaker or online at rodbuilding.org, it is imperative to get the contrast for the effect to take place once the overwrap is done. This seems to me from what I have done, is require a light and dark side by side. Don't get me wrong,please. I am NOT saying it won't work. All I am saying is that the person that pioneered this technique has specific parameters he has found to work, and work BEST. Perhaps by staggering or even adding a third thread to the base wrap,it can work better? Then again, they may work well even if not staggered. As long as there is contrast. It may just require a contrasting single color thread along with one of the threads you bought. If you get a base layer done, its probably not going to cost you much thread to see what can happen with the top layer, as it can always be unwound back onto the spool it came from. Provided of course you don't finish it.

Another thing to keep in mind is that what you get on a stripper guide base wrap won't work the same as at the tip, due to differing OD's at each end of the rod. At least the change would be a progressive thing. Its also one reason I never liked it for wrapping...too inconsistent.
As suggested by others, do some experimental stuff 1st and post your results for us. We need a guinea pigs sometimes. May as well be you.

Best wishes and luck,
Chuck