Sample Test Visual Style

Sample Test Visual Style (internally known as Mallard or Personal Visual Style) is a visual style included in some pre-release builds of Windows XP. As of 2019, the only leaked builds to include the style are Windows XP build 2410, 2416, and 2419, where it includes two color schemes, called Chartreuse Mongoose and Blue Lagoon (internally referred to as Paler).

The theme is first mentioned in a Whistler feature planning spreadsheet from 2000-02-22, which mentions a default skin set, which was specified to consist of a Consumer and Pro look, planned to be finished by 2000-04-28. The Taskbar and Start Menu Properties control panel in build 2257, which was compiled on 2000-08-10, includes a screenshot of the desktop with the new Start Menu open and a taskbar whose design shares many similarities with the sample theme later included in pre-Beta 2 builds. However, the screenshot doesn't include a watermark, therefore it is very likely to be a concept.

The  file embedded in   from early Beta 2 builds contains a last updated date of 2000-07-11. However, the same component in the Watercolor theme contains a last update date of 2000-04-19, which predates build 2250. Given that the Watercolor theme (then-named Professional) has undergone a major revamp between builds 2250 and 2257 and that the INI file itself has been updated several times in the lead up to build 2419 with the last update date staying unchanged, this value should not be considered accurate.

Raymond Chen tells in a blog post from 2006-01-11 that the theme had served as a decoy to distract the general public while the visual styles team had been working secretly on Luna.