Sample Test Visual Style

Sample Test Visual Style (internally known as Mallard) is a visual style included in some pre-release builds of Windows XP. As of 2021, 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).

A Whistler feature planning spreadsheet from 22 February 2000 mentions a default skin set consisting of a Consumer and Pro look planned to be finished by 28 April 2000, which refers to Watercolor (then-named Business) and possibly this theme as the string Personal Visual Style has been found in the theme files in early pre-Beta 2 builds.

The Taskbar and Start Menu Properties control panel in build 2257, which was compiled on 10 August 2000, includes a low resolution concept screenshot of the desktop with the new Start menu open, which is used to illustrate the respective option. A higher resolution concept with the same taskbar design, which shares some similarities with the sample style later included in pre-Beta 2 builds, has been found in resources of an IconFactory podcast.

The  file embedded in   from early pre-Beta 2 builds contains a last updated date of 11 July 2000. However, the same file in the Watercolor theme claims a last update date of 19 April 2000, 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 11 January 2006 that Mallard had served as a decoy to distract the general public while the visual styles team had been working secretly on Luna. However, given that Mallard was present only for a brief period of time after Beta 1, while Watercolor was present in most Beta 1 builds, it's likely that he actually meant the latter.

Despite the theme being removed from Windows XP builds after the introduction of Luna, it was still included in the source code of both Windows XP and Windows Server 2003.