Even with work attire becoming less formal, the suit is still the uniform of interviewing. If you don’t have one, save your money and go shopping because it is important in how you present yourself. Keep it conservative. You can always lighten up and match the dress code set by the example of your boss or other supervisors. Keep in mind that the interview is not a social occasion, so don’t be too stylish. Choose dark colors, long-sleeve white shirts or blouses, and minimal accessories or jewelry.
Note: The purpose here is not to make everyone look alike or disguise your personal style. The purpose is to try to ensure that your look does not distract from your spoken communication in the interview. If an employer is thinking about what you are wearing they are not listening to your message.