What Does Orange Signify?

Nothing.  In North America, with the exception of the Copperhead, snakes with orange on them are harmless.  In some, like the Ringneck, flashing the bright color might confuse birds that are trying to eat the snake, since in insects and other invertebrates that birds also eat, the color orange usually means the insect is either toxic, or will sting, or just tastes bad.  By mimicking the colors of those insects, small snakes can trick birds into leaving them alone.  Ringnecks, Red-Bellies, many Water Snakes and Corn Snakes are just a few examples of harmless snakes that have orange coloration on them somewhere.