The Windows Theme In CSS

CSS2 shipped the entire Windows Appearance control panel as colour keywords, so a page could dress up as the visitor's desktop.

In 2026: Partly. The keywords still resolve, so the demo renders, but browsers now map them to fixed values instead of the user's actual theme, because reading the real desktop palette was a fingerprinting vector. CSS Color Level 3 deprecated the original list; a slimmed set came back for forced-colors accessibility modes. The button below will look grey and Windows-ish forever, no matter what your desktop does.

Where it came from: CSS2 system colors, W3C 1998, named directly after the Windows Appearance control panel. MDN ↗

<style>
/* Paint your page with the visitor's actual Windows theme */
.win-button {
  background: ButtonFace;
  color: ButtonText;
  border: 2px outset ButtonHighlight;
  padding: 2px 12px;
}
.win-tip {
  background: InfoBackground;
  color: InfoText;
  border: 1px solid WindowFrame;
  padding: 2px 6px;
}
</style>

<p><span class="win-button">A Windows 98 button made of pure CSS</span></p>
<p><span class="win-tip">A tooltip painted in the visitor's own theme colours.</span></p>