Restain pressure treated deck with color

Hello,
My pressure treated deck is thirteen years old. It has been treated with Cabot semi-transparent stain over the years, approx. three times. It's overdue for another treatment but I am stumped by what product(s) to use. Living in Virginia, we have been dealing with lower and lower V.O.C. allowances over the last few years. The product I've used before is no longer available in the same oil based formula. My deck is a lovely slate blue color and I would like to keep it that way. It seems there are no products that you recommend that come in colors, other than wood tones. The closest I can find is Defy Epoxy stain in "driftwood gray". Is that my only reasonable option?
Also, despite my intentional avoidance of solid color stains that would need to be removed before re-staining, it seems that that's exactly what I'll have to do now. With all the re-cleaning and re-staining that is now necessary with water based products, hasn't the EPA created more pollution potential than was present in the past, with our oil based stains that lasted for longer than a year. Help!