Which PSU do you have, specifically?
Extensions are the same for any PSU, but custom sleeved cables need to run to the appropriate pin "outs" on the PSU.
Between retail kits from CableMod:
https://cablemod.com/
Customs from WazzModz
https://wazzmodz.com/paracord-standard-cables/
Or others, there's lot of options.
I think EVGA themselves even sell white sleeved cables, for certain PSUs.
https://www.evga.com/products/productlist.aspx?type=10&family=Power+Supplies&chipset=Power+Supply+Cable+Set+(Individually+Sleeved)
From a budget standpoint, white cable extensions are likely going to be a solid margin cheaper than fully sleeved, replacement cables.