As we know, the color of the eyes is not changed which is decided by the genetic endowment. However, you could wear the colored contact lenses to change the color of the eyes. You could base on your clothing and your color of the hair to wear the favorite color of the contact lenses to make your eyes look bigger and attractive.
Yes. Generally, when you wear some bright colored clothes, if you look at mirror, you may feel that your eyes color is a bit of different. This is normal. Certain color clothes will definitely bring out your eye color depending on the mix of colors. For example, if you have a pair of blue eyes, and you wear a bright blue coat, it will definitely accentuate the eyes.
What I heard about is just unnecessary I suppose. Because as you can see, the color of our eyes are inborn, which is primarily decided by our gene types and anthropological reasons. So, generally speaking, what you wear does not have any impact on the color of your eyes, so you don't have to worry about that. Sometimes you would have some illusions but that is not true.