It is because of The Great Red Spot. The Great Red Spot is a massive hurricane. Jupiter is nicknamed The Red Eye because of the Great Red Spot and it is also nicknamed The Gas Giant because it is massive and mostly made out of gas.
A black widow spider is black with a red mark on it's abdomen; this might or might not be what you meant. The black widow sometimes has a red mark on her back, as well. The red backed spider of Australia, a relative of the black widow, has an orange red mark on the back.