Pallette issues on image export

```
During image export in GUI and console versions the renderer uses the style
that corresponds to the OS's colors while it shoukd use white
background/black foreground. At least the user should be able to change that.

For now the 'black on white' images are needed.


```

Original issue reported on code.google.com by `boris...@gmail.com` on 12 Nov 2009 at 8:29
