@rugbygirl - Of course apples and bananas aren't "bad"! And they're certainly much better for you than most of the other snacks you could be eating.
The thing is that if those are all the fruits you eat, you're missing out on citrus bioflavonoids and other nutrients that brighter and darker fruits have. Try to branch out!
A good place to start is at your local farmer's market, if you have one. See what's in season. Oranges and pineapple are also among the most nutritious fruits, and you can get those year-round at the grocery store.
"Eat the rainbow" isn't just about the bioflavonoids, though that's one advantage. Each color - red, green, yellow, etc. - has different nutrients. Orange foods tend to be high in beta carotene, for instance. Try exploring different in-season vegetable options. There's a whole world out there!