CSS background properties & validator

so, i ran my CSS through a validator, and for the first time i’m ONLY getting 2 warnings!! :beer: anyhow, i’m not exactly sure how to fix 'em:

background-color: #CCCCCC
[color=red][size=4]Warning:[/size] The shorthand background property is more widely supported than background-color.[/color]

not sure what to do about this one…

html,body {
background-image: url(bkg.gif);
background-color: none;
margin-left:0px;
margin-right:0px;
margin-top:0px;
margin-bottom:0px;
padding:0;
min-width:800px;
}

[color=red][size=4]Warning:[/size] To help avoid conflicts with user style sheets, background and color properties should be specified together.[/color]

dont know how to combine them?

any suggestions?