In the Simpsons episode where Bart gets back on Nelson by getting an army, when Barts "army" does the saturation bombing (water balloons), Nelson has two friends, one has brown skin and one is the Simpsons' regular color (yellow). In one part, where Nelson and his two friends are being hit with water balloons and they are crouching down, both of them have brown skin. It's only for a split second, so you need good eyes.