Mine LOVE chopped grapes -- when I want them to try something new I add it to the chopped grapes. Sometimes they like the new food (strawberries) and sometimes they don't (peas). It's fun watching them lose their little minds over their treats. Chop up some watermelon and mix it in the with oatmeal and see what they do.
was the watermelon orange i find mine wont eat anything orange,used to offer them cooked carrots wont touch them, they love yellow melon and also fond of apples, and also tomatoes cut in half so they can get to the seeds but i think their all time favourite is baby gem lettuce hung from a piece of string in their run that would be demolished in minutes