A person wearing formal attire in an interview setting is assumed to be respectable and assumed to take up responsibilities. It is important to build a positive first impression. Formal clothes show the dignity and worthiness of the candidate. Appropriate dressing makes you look serious and interested in getting the job or the business deal. Wearing well ironed and tidy clothes is also very important. There should be no stains and no loose thread on your attire as well. Fitting and color of the dress should be suitable. It should neither be of vibrant colors nor of dull colors. A white shirt is often the best thing to wear while going for an interview.