I use AN-Vx (Silver), AN-Lexus (copper) and Crimson Cable (Copper) RCA interconnects between my digital front ends, preamps, and amps. I also have AN-SPx (Silver), AN-Lexus (Copper) and Crimson Speaker Cables. I never mix brands or models of cables, interconnects or speaker in any system configuration. I find them to all to sound different. The Silver sound "refined"; the Lexus are full-bodied; the Crimson are more transparent to my ears. They all fit different moods, music and Mfrs.
I’ve found a loom of pure silver for signal cables and all copper for power cables has worked together in my setup to make (for me) an ideal balance... and that all copper throughout worked in some ways but a shade too painterly in the system I had at the time (shindo pre and Maggie... silver is very much the shindo happy place) and the silver signal cables moved towards being in many ways truer and more cinematic.
That said I have long built my system around this choice so every component and setup parameter I have now has been decided based upon this combination.
I do use kiss as an overall system approach... so simple is sweet, I keep all the signal cables the same type and also same with power, generally go for the least components, less connections, in many ways essentially less complex is the mantra that works for better for me.
Though I am sure had I gone silver and palladium or gold alloy or all copper at that earlier time (if the cables were great iterations of their particular metallurgy) that I still could have made a system around them that built towards having appropriate balance and sounding right and natural. In the end it is the system mix that matters. We make our choices and take our own separate paths but hopefully all end together playing music in the happy place.