Actress Hailee Steinfeld pairs a navy-and-white dress with white strapped sandals at an event in Los Angeles in 2013.
If the oil is on the inside parts of the spark plug like the bottom insulator, that's a bigger issue, you have either leaking valve seals or very leaky piston rings. If your car blows a puff of blue smoke on startup, you probably ave leaky valve seals. If it blows blue smoke all the time, leaky piston rings.
Oil can leak from gaskets and seals on the front or rear of an engine, from valve covers or from the oil pan underneath, so there are several possibilities. Transmission fluid is usually reddish and slick, though some come in other colors and can be thicker or thinner than engine oil.