I wear a striped navy suit in my American office all the time. It works well for me. I certainly wouldn't wear a black suit to work, striped or not. What you would wear at the Venetian has no relationship (one hopes) to what you would wear at the office, where you deal with clients and those you hope will be clients. In your professional life, stick with navy and olive, and in winter (if you're in the appropriate climate) the occasional brownish tweed. Vegas? Black is fine. Hell, bowling shirts are fine. One more thing: don't look to movies if you're looking for sartorial guidance. Inspiration, fine, but if admiration of a look were sufficient we'd all look like Henry Hill in Goodfellas. And then we'd get the same reaction from our bosses that Henry got from his mother: "You look like a gangster." Not a horrible thing, necessarily, but not the best thing in the work context, either. Bottom line: you want to start with navy, and go from there. Pinstripes are fine, but get yourself a basic Brooks navy suit and work your way up. The fact that you're interested in dressing well is great in itself. Start with the fundamentals, and pretty soon you'll find you have thirty or more suits in your closet and this discussion will be purely academic.