Brown Recluse  Brown and sometimes an almost deep yellow color and usually has markings on the dorsal side of its cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nickname "fiddleback spider" or "violin spider". Coloring varies from light tan to brown and the violin marking may not be visible .

Black Widow
Adult female black widow spiders are gloss black with an hourglass shaped marking on the underside of its abdomen which can range from orange to red.