Board Thread:Questions and Answers/@comment-7657843-20161007190155/@comment-1031724-20161027220039

I heard it was revealed as an Infinity Stone. They must have explicitly said it somewhere, but I figured it was, because the Time Stone is one of the two left, and the only two unused colors are orange and green. I've seen pictures of the Eye with a green light, and it has time powers, so even if they didn't say it was, there is no chance that it isn't.

Meaning there is only one Infinity Stone left, the Soul Stone, which will be orange.