Final answer:
Iliana can pick four colors from the given six colors in 15 different ways.
Step-by-step explanation:
In this problem, we need to determine the number of ways that Iliana can pick four colors from the given six colors, where green must be one of the colors. Since order does not matter, we can use combination to solve this. We have 6 colors and we want to choose 4, so the formula for combination is C(6, 4) = 6! / (4! * 2!) = 15. Therefore, Iliana can pick four colors from the given six colors in 15 different ways.