Ties are bigger, bolder and more colorful. Ni en may still, for now, have a better time of it in the business world. Few can dispute, however, that when it comes to work wardrobes, men definitely get the short end of the fashion stick. The gray or blue business suit leaves little room for creative expression, and even males in more innovative fields, such as advertising and design, are severely limited as to what is de rigueur to wear. "One of the most notable differences this fall will be the wider silhouettes," says Robert Fischer, buyer for Kosins Clothes in Lathrup Village. For the 1991 season Mr. Fisher notes that ties stretch to well over three, and even approaching, four inches in width. "When ties get wider, they usually get bolder," says Jerry Andersen, of the Neckwear Association of America, a New York-based trade group. "You have a broader canvas to work with." This season, men can look forward to a look back — to the 1970s — with bolder colors in often unexpected, clashing combinations like bright reds and burnt oranges. Lighter, dustier shades like cadet blue replace navy, and earthtones