Polka dots were recorded in fashion history as far back as the 1800′s and it is a pattern that has long been associated with dance. This is probably why swing dresses are popularly available in polka dot.
Here is a picture from Corsets UK, a beautiful demonstration of how polka dots can highlight curves and contours.
Of course the fabric is available in many different colour combinations. Unless you are going for a psychobilly look, I prefer to stick to white on black or red on white.