As a professional deck builder & LGC, my first recommendation (and what I plan to upgrade to) is Ipe. There are a lot of other tropical hardwoods out there. Mahogany, Camberra, Cumaru, Teak, Purpleheart, and many others. ALL will turn gray in sunlight unless protected by a uv inhibited sealer. TWP is great - and first choice - for pressure treated southern yellow pine. Sikkens or Cabot Australian timber oil is a better choice for tropicals. The natural oils in the tropicals aren't very compatible with any stains/sealers than aren't specifically formulated for them. Tigerwood isn't as dense as Ipe, but very pretty. It doesn't get as hot as other hardwoods, either. Post some pix, please. And some more later in the fall. It would be interesting to see if it changes any.