The waistcoat is an almost compulsory accessory for the formal outfit, yet not undermining the dinner jacket. It must be in white when matched with formal evening dress but it may be in any other colour when differently matched. It can be made of the same fabric as the suit or jacket or it may be a contrasting element. In both cases, the neck accessory must be matched with the waistcoat. During a formal event the waistcoat plays an important part when the jacket is taken off and it outlines an elegant look for the wearer.