It's all made out out of similar material.. and it's not hard.. but what is hard is getting the lengths right and that includes yokes.. miss it and it'll be out of tune for ever. There are some good shops that's all they do is make hi performance cables out of Dynema and similar materials.
Here's a couple shops that have good reputations
http://catfishcustombowstrings.com/shop/44957
https://www.hogwirehunt.com/products/
https://twistedxbowstrings.com
These guys will make what ever material and color you want and it'll be right...