I am also getting an aqua background with red text when i look on my forums, and as previously said i cant find anywhere to change the colour settings, anything that can be done about this ?
Admin > Ranks. Set the post color text.
Thats an odd thing I have noticed with the preview function. It doesn't follow the color formats. Its one thing the preview for wording and spelling but its another to look at it for tag and color formatting when it uses your sites default color schemes and ignores and rank specific background or foreground color combinations.