Juice any combination of vegetables and fruits and add a little kale,spinach or any dark leafy green. You will end up with an awful looking brown if you combine different colors. To make it a little more appetizing, appearance-wise, add about a one inch chunk of red beet. The color is so vibrant that it will immediately turn your juice a lovely ruby hue. You also get an added boost nutritionally from the beet.
Good luck and happy juicing!