I made cushions for all my chairs on the front porch which are covered by a roof but still they faded after a couple years. Also made cushions and recovered some folding chairs for the back deck, again they faded. Used outdoor fabrics too. Sunbrella I thought was supposed to be fade resistant but guess not. Then a silly squirrel decided to start chewing on my loose pillows on the front porch so had to make new anyway. Still have some outdoor fabric leftover so will use it to make new cushions for the wicker chairs as they will go out back now that I have a sunroom and new patio. I'm sure it will fade and get wet. I did buy some of the Scotchguard water resistant spray but couldn't tell you if it worked or not.
As I did a lot of vinyl embroidery garden stakes I have lots of the vinyl leftover and trying to find a use for it. Thinking of using it in strips to make new cushions for out back. I know vinyl will become hot in the sun so may have to rethink this but at least its water resistant if nothing else. Cork fabric would be softer but its so expensive so will keep searching for ideas.