You should be able to shoot 12 strand dacron on that bow, with out all that creep! That is, if it was quality built!
How much twist is in it, would be my first ?. How much "twisting" experience, does your friend have! Have him build ya another to replace it.
When we all start making strings, we have to"use" friends! :D It's part of the R&D dept.
As for the question on colors, back in the day of "Dacron Only", talk was, that the dyes weakend the strands sum what! Even white, was not the natural color!
Whatever, we have slept since then. It's all good!