It is always fun to experiment with different things such as changing up your hairstyle or eye color. For a new model or actor starting out it is always best to attend a casting call or audition with your natural eye color.
You don’t want to take away from your natural beauty especially when the point of an audition is to convince the casting director that you’re right for the role. they are not picking you because if your look, they are booking you because they think you fit the role. Natural is always recommended.