Which fabric should I use for cushions on an outdoor antique glider?

I have this thought from an antique glider I saw at a boutique once with pastel shabby chic euro pillows in pinks greens and creams. Thus far, I have been unable to find outdoor fabric in the colors I want, so is there another fabric that I could use? I would like to use something soft and have more couch-type cushions on it instead of a flat foam form and rough outdoor fabric. I live in Texas (in the Brazos Valley area) and wonder about mildew and lifespan...