Fijian Mahogany

We have an almost 2 year old Fijian Mahogany deck. We are struggling to keep stain on it. The first brand of stain lasted 6 months and the second lasted 2 months. We live at 8500 ft in Colorado, so it gets its fair share of sun exposure (full sun). I have read and we knew that the deck would need to be maintained annually. At this point we would be happy if it lasted a year. Both times the staining was done by professionals that sanded and cleaned it before the stain went on. We are just trying to find out the best option this time around. I read your reviews on the IPE Oil Hardwood, Messmers UV Plus for Hardwoods and Defy Hardwood. Could you please recommend a product that might get us through a year? We want to make sure that we are doing the right thing for our deck. Protection and keeping the beautiful color (orange/red brown) are our goals. Also, what color would you choose to keep closest to the true color of the wood? I see the IPE Oil doesn't have a color. Thanks so much for any advice you can give.