I shold like to put a tjock text on a background with different colours. How can I suit the colour to the background, to get the complementary colours? Just now I have only black-and-white,backround and I need a black-and-white text, with white letters on black background and black letters on the white background. It would be fine if this changing could happen even through the objects in the forground, so even the part of the letters could accomodate.