As of now there's 38 different perk deck colors/designs.
Pictures of 'Flags' -> https://imgur.com/a/nDIRaSj Pictures of 'Gradients' - > https://imgur.com/a/zztx0bQ Pictures of 'Specials' - > https://imgur.com/a/XRcFhDI Pictures of 'Solid Colors' - > https://imgur.com/a/uMKiqsZ Pictures of 'Twitch Streamers' - > https://imgur.com/a/R5h6uGC
Pictures can also be found in the folders.