Believe it or not, maroon gave the most consistent results.
I know many are claiming its snake oil, but today ive placed both speakers side by side, sent identical mono signal to both sides, one with the GR and the other with a cheap generic cable, and toggled L and R to do the A/B test.
The difference was so loud that you had to be deaf not to hear it..
Maybe the "Guinea pigs"(your language) were actually deaf people...? was that option taken under consideration?
Looks like they were much more receptive to color...;-)