The picture in your question shows the answer: Most lighting in the cabin is done indirectly, so you don't see the light source directly. Instead, light is reflected off the cabin interior. If you would paint that interior in gaudy colors, you would have undesirable effects. Colored surfaces absorb some wavelengths, so the brightness in the cabin is reduced. Plus, the selective reflection will shift the color of the light.
- Newspaper and magazine paper would not be white anymore, but have the color of the cabin interior. As @mins correctly points out, the brain can compensate for this. It will, however, make it difficult to read text printed in the color of the cabin interior because it would no longer stand out from the background.
- The color pictures in the magazines would look funny. If you now think people could switch on the reading lights: Note how few passengers actually know how to operate them.
- The food you get served would look funny. It is already not a pleasure to look at in most cases, but in colored light it gets even worse.
While it might be fun momentarily to be in a room with mood lighting, being exposed to this one color for the full length of the flight without a possibility to escape (except for closing your eyes) will offend most passengers.
Although not the original reason, modern plane interiors are designed to keep people calm. Boeing has a nice article on it here that is worth taking a look at.
Color psychology plays an important role in developing the overall look. Studies show that people in different cultures associate certain colors with similar emotions or concepts. Blue/green is nearly unanimously associated with peace. Pink and lavender shades connote love, while blue/purple may signify nobility.
The darker colors of seats can also aid in hiding stains and dirt better than say white or tan leather (which is found in a lot of GA planes).
As has also be mentioned in some of the comments white plastic is how most plastics are made thus its most likely cheaper to order something in white than have it colored.
There are some emergency implications to interior colors. In the case of an emergency you want the exits to be clearly marked and easy to find. If you have a "busy" interior when it comes to both over all design and color you can have issues making an emergency exit that contrasts well enough to see when it needs to be seen.
For what it's worth color has been tried (then again, it was the 70s). Now think about a red emergency light going off in this plane, it would barely stand out. (source)