How to find good looking font color if background color is known?

\n"); // try 4096 colors for (r = 0; r <= 15; r++) { for (g = 0; g <= 15; g++) { for (b = 0; b <= 15; b++) { int red; int blue; int green; double cDiff; // brightness increasse like this: 00, 11,22, ..., ff red = (r << 4) | r; blue = (b << 4) | b; green = (g << 4) | g; cDiff = contrastDiff( red, green, blue, bred, bgreen, bblue ); if (cDiff < 5.0) continue; writeDiv(red, green, blue, out); } } } // finalize HTML document out.write("