As such, there is no law governing the color of Posted Signs. However, Posted Signs must be “conspicuous” enough to be spotted from a distance by a person who is about to enter your property. Yellow is a preferred color choice because it gets attention even in cluttered spaces and indicates some kind of “caution”. As a property owner, it is your duty to make the signs visible and conspicuous, without being an eyesore. Hence, black text on a yellow background is a great choice. Other color schemes are also available including orange, red, black & white, etc.