awataha-
I went and took some pictures and saw what you meant by dull. Scratch my last answer.
I'm going to assume you use the LCD to compose your picture (please correct me if I'm wrong.) You're going to want to press the button that switches from LCD to the veiwfinder (looks loke a tv screen) then, press the info button. You'll keep pressing until you get this screen.
I have the saturation function highlighted. Next to it is gradiation tool. And below that is the color management tool. (AdobeRGB and sRGB are the choices) You can fiddle arround with buttons until you find the color you like.
Let me know how it turns out.