My TecnoArm is indeed on the bright side when used with a bright cartridge. But it is mellow when used with a warmer cartridge.
I can't comment on the effect of tonearm wiring because I've heard no alternatives for comparison. But the i/c cable between my phonostage and pre-amp has been examined. Silver cable is bright when used with a bright cartridge. It is mellow when used with a warmer cartridge. Copper cable behaves exactly the same.