The problem is that the colour can confuse the metering on my camera. So in an effort to get a handle on this, I've tested three different background with two cameras to see what happens. In all the shots, the left hand is a Cannon G12, the right, a Fuji S9500. All I've done is crop and re-size the images. Normally, I'll fiddle with the settings to get the best result but I was interested to see how they looked un-tweaked.
First, Electric Blue as mandated by Airfix Magazine:
Next, Pale Blue, the colour I use for Hornby Magazine:
Paler colours seem to confuse the camera a lot less than the electric blue so whites and creams are better reproduced. I suspect that the G12 metering needs practise since the background colours are spot-on but at the cost of the colours of the photo subjects.
The older camera fades the background but seems happier with the foreground. This is probably be nearly 9000 photos in, I'm more comfortable with it than my newer toy.
I am sure I prefer pale background. The trend in publishing is towards more cut-out photos with no background at all to let the designer do their thang. White backgrounds make the cutting out process a lot quicker and easier.