Originally Posted by
Patrick Chase
White walls help you in three ways:
First, they help you avoid mixed color temperatures within an image. As an example of what you don't want, if you have a blue wall then you'll end up with fairly warm lighting on surfaces that are illuminated directly from your light source, and cold lighting in the shadows where most of the light is bounced in. There are cases where you may want that effect, but product photography usually isn't one of them. The same thing happens when you mix flash with ambient, unless you filter the flash to match (some recent phones can do that automatically).
Second, white walls make life easier for the automatic white balance (AWB) algorithm in the camera by providing a large neutral highlight reference. Most cameras only shoot JPEG, so you're more or less dependent on the camera to get AWB right the first time. If you're shooting RAW with a "real camera" (tm) then this isn't such a big deal since you can clean it up easily in post.
Third, white walls help keep the scene range within the dynamic range limits of those itsy bitsy sensors by bouncing light into the shadows. Again not as big of a deal with a "real camera".
On a quasi-related note, have you ever tried cross-polarization? It can really bring out the color in higher-gloss finishes, though at the expense of potentially deadening their appearance. You can even do it with a phone cam...
Way OT now, except that we are talking about photographing furniture :-).