Well, of course not. Even if you have taken the cornea transparent, your eye color will not change. You should know that after you have cornea transparent, the cornea will be clear and transparent. But it will have no effect on the color of your eyes. Also, the only thing that would happen to the color of your eyes after a cornea transplant might be that the color might be a bit more vivid than before, because the new cornea might be more transparent than the old one. Anyway, there is nothing to do with your eye color. So you do not need to worry about it.
If you mean brown to green or blue, the answer is NO because our eyes is genetic, but it may appears red after the surgery, while, you do not need to worry about it, because it will disappear after several days. Following the doctor's suggestion and have the regular exam after the surgery, hope you're recover soon.
Are you kidding? You should know that corneal transplant is designed to make you see things again because you were on the brink of blindness. With new corneal , you regained the ability to see, however, the color of your eyes would not be changed, because corneal is not the substance that is colored. So, you should not be worried about it. It simply has nothing to do with the eye color.