1. <html> is the ROOT element. It is the first, and EVERYTHING is inside it.
2. There are 2 children of <html>, the HEAD and BODY. There is NOTHING else.
<html>
<head>
some crap..
</head>
<body>
some crap..
</body>
</html>
DIVs cannot be placed outside of the BODY. Whoever told you this is right, is
WRONG. It is much better to style BODY if you wish to apply a background color to the BODY.
body {
background: #470;
}
Will suit you fine. This is the simplest and best way to do it.
Here are a couple of other tips. I see that you have a link to an external stylesheet. I don't know why it's in UPPERCASE considering everything else isn't, but I'm guessing you copy pasted it. That's perfectly fine, but try keeping everything consistently sized.
Also, always have a DOCTYPE at the top of your HTML documents. It tells the browser what "rules" its conforming to. Try something like HTML 4.01 Strict, or HTML 4.01 Transitional.
Read about it
here