To set the colour of the fractal's interior
1) On the Options menu, click Colour Palette.
2) On the Colour Palette window's Colour menu, click Interior.
3) Adjust the red (R), green (G), and blue (b) sliders to the desired colour.
As you change the values, the interior colour of open fractal windows changes accordingly to make it easier to see how a particular interior colour will look.
4) Click OK.