Wicker: The UV fabric on the cushion is fade, water and chlorine resistant and specifically designed for outdoor use. The fabric comes with a 2 year warranty against fading

Teak, If you do nothing to your teak it will grey naturally. It is recommended to clean your teak once or twice a year with a teak cleaner to remove accumulated dirt. You can also purchase a sealer and apply it annually to protect your teak from weather. Bunnings sell a marine grade sealer for teak. Oil your teak with orange oil and this will feed the wood and prevent it drying out.