Answer:
The business attire landscape is changing so much in response to the lightening speeds at which our lives are now paced and the need to deal with only the most critical issues that affect getting the job done. However, still paramount to getting new clients, new customers, new allies and employers (and maintaining them) is presenting an appealing image that conveys confidence, solidity and attention to detail.

Image and Roles
Not only does the candidate need to be conscious of presenting a professional image. The business (and those who operate it and in it) needs to convey that sense of professionalism and instill in the user confidence in whom they choose to use.

The role a person plays in the workforce and their social position usually becomes quite obvious because of their attire. The executive or manager usually wears a suit made of better to best quality natural fabric that has subdued or dark tones. The dark tones provide a subtle frame for the person. Additionally, the person carries him/herself with good posture, a steady, well-modulated voice punctuated with splashes of enthusiasm and colored with different ranges of tone befitting the idea being discussed.

A Sea of Navy Blue
Many schools teach going to the interview in the traditional navy blue suit. So everyone talks about wearing their navy blue suit to the interview. After seeing several dozen candidates, the recruiter or hiring manager may discuss the potential candidates who were interviewed and a possible scene in the conference would sound something like this:

"Well, I really liked this one. They had some good things to say."

"Oh, which one was that?"

"You know, the one who wore the navy blue suit."

Or imagine this type of announcement.

"Will the person who's visiting today and wearing the navy blue suit please come to the desk. We have a very important message for you."

Wearing a navy blue suit is good advice but think about what the underlying meaning is. What they're trying to say is avoid going in wearing something that's so flashy it detracts from what you, the candidate, are, have to say, and can do. Do not wear something that will distract from you and your talents.

However, the other part of the formula for what not to wear is do not become so much a part of the interviewing uniform that you become one in the sea of navy blue suits. Now that you've distinguished yourself through your resume, show some creativity for making yourself stand out in person.

The Right Color
Just remember that green, for some reason and no matter what shade, is a turn-off during interviews and sales presentations. Don't wear it. Women should avoid pastels and flowered prints. It indicates weakness and sentimentality. However, if you're going into a situation where you need to convey empathy, this may be an alternative. Patterns, prints, checks, houndstooth, plaids and the like, no matter what color, detract from power colors and power.

Power colors are dark and jewel tones. Consider, in addition to navy blue, shades of gray, black, dark brown, tan or beige. And if you have a lot of personal experience and talent and know how to keep the attention focused on you and your abilities, you might be able to get away with wearing red. With red, make certain that any other clothing is extremely understated.

Know the Venue
The other thing to take into consideration when going to an interview is the size of the company, the corporate decorum, the ages of the people who work there, and the type of industry.

If you're going to a dotcom company, chances are that everyone wears casual clothes. So you would do yourself a favor to leave the gold jewelry and the tailored dress or suit at home. This does not, however, mean that you should arrive in casual. You want to impress for heaven's sake! For men, slacks, a soft-colored shirt, a sports jacket and a (yes) tie. For women, trouser slacks, a knee-length skirt (or dress), soft blouse and coordinated jacket is fine.

A Few Words About Scent
Please leave off wearing that wonderfully seductive and strong cologne. You want to leave a sense of your abilities, not your strong perfume that gagged everyone in the office. If any scent*, wear something that is extremely subtle and natural (no rose-scented perfumes, please!).

Good Example
I recall sitting on the bus next to a young man some time ago. He was dressed in black pressed and creased better cotton blend slacks, loose but tailored and fitted. He wore a navy pin-stripped shirt that was also pressed and creased. His sports jacket was dark and just as fresh looking. No lint, no burrs, no plucks were anywhere. He was clean shaven except for a small moustache. His hair looked like he used a barber on a regular basis. If he wore an earring, it was not noticeable.

What finally caused me to speak to this young man was the fact that there was a subtle scent of fresh soap that seemed to come from him. It reminded me of my favorite perfume that has a bit of citrus base. So I asked the name of the scent. He expressed concern that he was overwhelming the bus. I assured him that definitely was not the case and the subtleness of the scent was what caused me to ask.

After a bit I also noticed a small portfolio he carried. I didn't ask. I decided he was going to an interview for a sales position. He also spoke politely with good, formal English in well-modulated tones. Based on his dress, the confidence with which he carried himself in all situations (including an unexpected emergency), his resourcefulness and ability to stay level-headed and calm while getting information and taking minor control of things as required, I decided he was going to get the job. He was suited to a T.

* Bear in mind that there is a population of people who are scent intolerant. Your interviewer or a critical player in the company just may be one of them.