That should not happen.
Are you sure you just didn’t start looking at your eyes more, subsequent to your conjunctivitis? Perceived iris coloration will, of course, change with your attire and environmental conditions.
What does your optometrist or ophthalmologist have to say about the sudden iris color change?
Never went back to the doctor, but believe me, I looked at them enough during the Pink Eye to know that they definitely changed color, and it was even obvious to people who know me and they noticed the change. They are not as light as they were after the Pink Eye. I had it in one eye then the other then back to the first one. That stuff nearly killed me! The eye color changed when a friend of mine had it, too.
Recent eye test and there is nothing wrong with my eyes.