CSS newbie, please help?!?

[5uperfly]

Hello everyone, this is probably a very silly question, as I am very new, and only just teaching myself css sheets, but here goes.

I have set up a styletype called Nav, as follows...

.Nav {
font: 12px Arial, Helvetica, sans-serif;
font-weight: bold;
color: #CC0000;
}


But when I go into a css checker, I get the following error messgae...

Warning: To help avoid conflicts with user style sheets, background and color properties should be specified together.

This happens on every instruction, and I can't figure it out. It doesn't seem to be causing problems in any browsers (ones that I have checked anyway), so should I just ignore it or am I doing something wrong?

Any help much appreciated, as I am only just learning these css thingies, I want to get it right now so I continue to get it right.


Thanks

[the tree]

If the warning wasn't self explanatory, then maybe read this (http://www.w3.org/QA/Tips/color).

[5uperfly]

That was much more explanatory than the book I am reading. That helped a lot.
Thanks