I have separate kegs and picnic taps for my sour beers along with separate tubing, auto-siphon, and wine thief. All is properly marked so I don't mistakenly use it on my normal beers. This just gives me peace of mind when incorporating those brews into my normal rotation.
I know some do not worry too much about separate kegs as long as you take them fully apart and soak all rubber pieces and metal in hot PBW, followed by a hot rinse(s), along with appropriate sanitizer prior to filling. But, once again, I would hate to inadvertently contaminate a normal beer by accident because I used a keg/tap for a sour/brett beer before it.