In the thread http://forum.high-logic.com/viewtopic.php?t=2252 Bhikkhu Pesala included the following.
If you want white text on a black background, then you need to add black contours enclosing the entire glyph, and fix the contour directions from the Validation Toolbar.
It occurs to me that doing that is presently a task which could take quite a time to carry out. An Inverse facility in the Effects section of the Glyph Transformer could automatically, for each glyph, add an extra contour of the correct width and change the direction of all of the other contours.
Some manual adjustment might be needed if the original font had any contours touching the edges of the glyph area, yet most of the task would have been done by the Glyph Transformer.
8 May 2008