As you can see in the screenshot below 3129 does not seem to use themed controls in the ‘Save Changes?’ dialog. Issue can be reproduced for any such dialog that includes Windows common controls.
Sublime Text 3129 x64 portable
Windows 10 Pro x64 v1703
I believe this is referred to as Visual Styles, and something needs to be declared in the manifest file to enable them:
old book with some comparison
MSDN article about how to enable visual styles in common controls
how common controls look in Notepad:
how they look in ST build 3126 x64:
how they look in ST build 3129 x64 on Windows 7:
EDIT: yeah, build 3129 is completely missing a manifest file. Here is build 3126’s, which correctly references version 6 of the common controls necessary for visual styles:
<?xml version='1.0' encoding='UTF-8' standalone='yes'?>
<assembly xmlns='urn:schemas-microsoft-com:asm.v1' manifestVersion='1.0'>
<trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
<security>
<requestedPrivileges>
<requestedExecutionLevel level='asInvoker' uiAccess='false' />
</requestedPrivileges>
</security>
</trustInfo>
<dependency>
<dependentAssembly>
<assemblyIdentity type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*' />
</dependentAssembly>
</dependency>
</assembly>
Thanks for the reports, this will be fixed for the next build
