I believe the lights are an independent variable in this experiment, so the outcome would be that they all grew equally (given that they were all exposed to an equal amount of light).
Correct me if I'm wrong, anybody.
To test the hypothesis that plants grow faster in green light, a student set up 3 of the same type of plants. She placed the first plant under a green light, the second plant under a regular light bulb, and the third plant under a red light? The outcome?