Dress code for an interview should follow some unsaid and unwritten rules.

For men, commonly worn black suit is a strict no, as it comes with a funeral connotation attached to it. A navy, gray or discreet pin-striped suit with two or three buttons, with the bottom button left undone is perfect. A white cotton long-sleeved shirt, silk tie, only in a solid color or geometric pattern, lace-up leather shoes that match the belt and black or blue socks are obligatory.
Tattoos should be covered and facial hair should be shaved. Hair should not touch collar and the watches should be essentially metal. Strong colognes or perfumes look too loud.
For women, it is ok to wear black, but gray, blue or camel-colored outfits are always recommended. Blue suits tell that you are trustworthy and gray suits say you're conservative.
Anything red, suggests your aggressive nature. Black shoes no taller than 2 inches and flesh-colored pantyhose are appropriate. Hair should neatly done in a ponytail or bun if longer than shoulder length.