Choose colors that will not blend together and opt for combinations that are easy on the eyes. While red on black is not a very readable choice, if that is what you want, fine. Keep in mind, however, that by choosing tone-on-tone variations you are sacrificing readability. If your potential customers can’t easily read your sign, chances are they’ll ignore it. Over the long haul, that can result in a significant loss of business. In most cases, the farther away you can read your advertisement the better. Some good color selections are yellow with black, yellow with green, white with any dark color (i.e. blue with white, red with white, etc.). The key is to choose colors that sharply contrast each other so as to leap off the design. If you’re still set on using dark combinations, like red on black, consider outlining the edge of your letters in white. This technique allows for separation between the colors and will attract your audience’s eye much better, Bumper sticker.