Is there away to display a user’s system colours?
Yes, through CSS. In CSS2, there is a set of unique colours based on system features (such as InfoBackground and ButtonFace). These get deprecated in CSS3, in favour of even more specific values. The proposal calls for a new property called appearance which simultaneously affects a variety of values (colour, font, background, padding, border, and margin). There are also new values for font, drawn from the system settings. Finally, the cursor has a number of more specific values, too. The many of the values in the last two additions are currently supported by Internet Explorer.