Automatic font colour for text in table

I have 2 master slides: 1 with black background, 1 with white background.
I created a table, and set the colour filling of the cells as empty.
I wrote text to the cells, and I set the font colour to automatic.
With the white master slide, the text in the cells is visible.
With the black master slide, it is not - how do I make it change automatically to white, when using this master slide?