Recommendation for an audiophile speaker cord that is not "bright"?

Anticables, really tough to beat
then if ya want to spend a bit more money an Audioquest with DBS, stock to copper

have fun, enjoy the music and the search 

Cardas are known for warm sound, except the "Clear" model.

Look into WyWires. All copper... no silver or silver plated. I used to be a big fan of silver cables but as my humble system has become more refined I’ve gone back to copper. WyWires have great balance and don’t draw attention to anything; they just get out of the way. Only listened to the Sasha’s with a Gryphon Diablo 300 in a store, but it was very revealing and I would have preferred a little more warmth. Not sure what model but they were running but they were using Transparent Cables. Sound was too hot for me but was very dynamic but not fatiguing but still too hot for my taste. Source was an Aurender N100 I believe. Not knowing the rest of your system or your room it’s hard to know if it’s the Nordost or not but my experience with other Wilson speakers is they are very revealing and I feel they require more system matching than other speakers. I use a mix of Nordost as well but not the upper level stuff but I do find they blend well with WyWires. You’re just going to have to experiment and find what’s right for you. What is the rest of your cable loom and what speaker cables do you personally own? You mentioned the Nordost are a friends. Upper level Cardas might be another line to look into. 

Kimber 8TC should do the job for you.

Anticables were mentioned. I tried them and found them bright; and others have, too, so I'd proceed with caution.

Consult with The Cable Co and have them send you options to audition firsthand (if you are in the U.S.).