Start with the embarrassingly obvious. Is your stylesheet in fact named stylesheetcss.css ? Is it only the color names that aren't coming through, or also the other properties? What about the rest of the CSS? You've got a class = "code" that you didn't include in your example.
Color names in the format you've used need a leading # or they will not be recognized.
Most important: Your DTD is in the wrong form. Feed it into the validator as a direct paste-in (I filled in the missing line as ... "DTD/xhtml1-strict.dtd"> ) and it will spit out 30 errors, most of them fixable by a single change.
Throw out the xml line, which you don't need, and replace the next few lines with
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
<html xmlns = "http://www.w3.org/1999/xhtml">
<meta http-equiv = "Content-Type" content = "text/html; charset=UTF-8" />
and the validator will be much happier.
When you say "second row" do you mean the first non-header row, or the second row of ordinary cells? Does it do this in all browsers?