What does "off" and "how they should be" mean to you? It is very hard to comment without knowing what they were exactly, and what you want them to be.
With digital photography, you can have any colors you want if you know what you are doing, so I don't think it is appropriate to blame the 400D if they are "off" to you. You have to fix it, either in camera, or in post.
Fist guess, and just a guess, start to control white balance. The EXIF info says your camera was in Auto WB, and this looks like shade. Try using the Shade setting for WB and see if you like that. But the solution is for you to learn to manage your colors the way you want.