Setting the default theme in Wine can make things look truly slick. Observe superm1's post in this thread: http://ubuntuforums.org/showthread.php?t=206366
The Human theme linked there seems ideal for integration, but Wine's theme support isn't stable enough to default to it. Another quite effective change is to make wine's colours match the Human theme. This is of course stable and doesn't have any speed penalty. The following colours achieve this quite well (circa edgy):
ubuntucolours.reg (import via regedit or paste colours in ~/.wine/user.reg . Change [HKEY_CURRENT_USER\Control Panel\Colors] into [Control Panel\\Colors] if you paste it)
Windows Registry Editor Version 5.00 [HKEY_CURRENT_USER\Control Panel\Colors] "ActiveBorder"="239 235 231" "ActiveTitle"="210 141 70" "AppWorkSpace"="177 170 163" "Background"="0 0 0" "ButtonAlternateFace"="181 181 181" "ButtonDkShadow"="115 106 96" "ButtonFace"="239 235 231" "ButtonHilight"="253 250 248" "ButtonLight"="239 235 231" "ButtonShadow"="179 175 171" "ButtonText"="0 0 0" "GrayText"="179 175 171" "Hilight"="248 206 140" "HilightText"="0 0 0" "InactiveBorder"="239 235 231" "InactiveTitle"="239 235 231" "InactiveTitleText"="60 60 59" "InfoText"="0 0 0" "InfoWindow"="239 235 231" "Menu"="239 235 231" "MenuBar"="239 235 231" "MenuHilight"="248 245 242" "MenuText"="0 0 0" "Scrollbar"="203 193 183" "TitleText"="255 255 255" "Window"="255 255 255" "WindowFrame"="0 0 0" "WindowText"="0 0 0"
[ReeceDunn]: I have some patches sent to wine-patches that make it possible to import a human.theme file. As of 12 Feb 2008, only some of those patches have been applied.
[ReeceDunn]: The remaining patches are now in, as of wine 0.9.59 (mentioned as fixed in the 0.9.60 release notes).
The human.theme file that does the same thing as the colour registry file above, but more cleanly, is:
[Theme] DisplayName="Ubuntu Human" [Control Panel\Colors] ActiveBorder=239 235 231 ActiveTitle=210 141 70 AppWorkspace=177 170 163 Background=0 0 0 ButtonAlternateFace=181 181 181 ButtonDkShadow=115 106 96 ButtonFace=239 235 231 ButtonHilight=253 250 248 ButtonLight=239 235 231 ButtonShadow=179 175 171 ButtonText=0 0 0 GradientActiveTitle=210 141 70 GradientInactiveTitle=239 235 231 GrayText=179 175 171 Hilight=248 206 140 HilightText=0 0 0 HotTrackingColor=253 250 248 InactiveBorder=239 235 231 InactiveTitle=239 235 231 InactiveTitleText=60 60 59 InfoText=0 0 0 InfoWindow=239 235 231 Menu=239 235 231 MenuBar=239 235 231 MenuHilight=248 245 242 MenuText=0 0 0 Scrollbar=203 193 183 TitleText=255 255 255 Window=255 255 255 WindowFrame=0 0 0 WindowText=0 0 0
Mostly working script to scrape GTK's colors and use them in Wine: http://www.endolith.com/wordpress/2008/08/03/wine-colors/