I was just looking at the site for making hard candy that was posted. good info except fo r one thing. it said take the candy until 310F which is perfect, thats the stage known as hard crack stage, or simply hard candy stage. but the article says to go another 10- 15 minutes on high heat!!!! no way, in fact once you hit 310 there is no reason to go any further. unless you just want a darker color, but it will soon start to over caramlize and acidify, and thats just not good eatin!
other than that what dina posted should work great, you could just make a strong green tea with the water in the recipe and sub it.