Today, for the first time, someone actually managed to make their entire post disappear on my flist because their chosen font colour was exactly the same as my background colour. Several times I have seen light pink, and all I can say is "Ow" because my background is light grey.
Leaving the font colour default means it will show up correctly on all layouts.
If you really need to change a font colour to make a point, make sure you change the background of the font to the correct colour as well like this.
This was done with the following code:
Just as a side note, you can also use the above code to hide warnings so people can choose to read them or not, if you want to. In this case 'color' and 'background-color' are simply the same value.
Warnings: character death (highlight to read)