Incorrect color on Windows 10/11

[C0m3b4ck]

I compiled my program using FPC 3.0.0, x32 target. When I run my program on Windows 10 and 11, smaller forms without TPageControl and TTabSheets have the correct color (clBlue). However, my form using TPageControl and TTabSheets is set to white, screenshots below, with the area not included in TPageControl being blue.

What is the solution? I'm sure it involved setting parent color and gettting color after parent.

Thank you for your time! 

[dseligo]

However, my form using TPageControl and TTabSheets is set to white, screenshots below, with the area not included in TPageControl being blue.

Where is TPageControl in your screenshot? Can you post design-time screenshot of the form?

It would be better if you make small demo program which shows your problem and post compilable files here.

You can try something like this (I don't know if it works in Lazarus 3.0, I use 4.4):

Code: Pascal  [Select][+][-]

1. uses UxTheme;
2. ...
3. procedure TYourForm.FormCreate(Sender: TObject);
4. begin
5.   SetWindowTheme(TPageControl(PageControl1).Handle, nil, '');
6. end;

P.S.: This works only in Windows.

[Zvoni]

You can try something like this (I don't know if it works in Lazarus 3.0, I use 4.4):

He's using Lazarus 1.6.2
His FPC is 3.0.0

[Martin_fr]

It's probably either missing or out-of-date manifest.

No idea, if/where that can be changed in 3.0.
In current versions "project options" have settings on the "application" page: "use manifest / enable themes"

It may also be, that Lazarus/LCL 3.0 just doesn't support newer themes... (maybe something old is hardcoded somewhere)

[Zvoni]

It's probably either missing or out-of-date manifest.

No idea, if/where that can be changed in 3.0.
In current versions "project options" have settings on the "application" page: "use manifest / enable themes"

It may also be, that Lazarus/LCL 3.0 just doesn't support newer themes... (maybe something old is hardcoded somewhere)

OP is using Lazarus 1.6.2
His FPC is 3.0.0

[C0m3b4ck]

Yes, I am using Lazarus 1.6.2 with FPC 3.0.0 for backwards compatibility. While reading much deeper, I found this solution: https://lists.lazarus-ide.org/pipermail/lazarus/2016-October/229882.html

It involves disabling manifest like Martin_fr mentioned, because Windows DWM (in versions Vista+) forces white background when manifests are on. However, upon running the app on modern systems, it will have the Windows Classic (9x) theme. For me, that is not worth it just to keep background colors.

Since I am planning to ship a separate x32 and x64 build anyway, I will try to compile using FPC 3.2.2 with Lazarus 4. Will report on how it goes.

[C0m3b4ck]

I initially feared that disabling Manifest would make my app have the Windows Classic theme - that was proven wrong. I recompiled my app on Windows 10 with disabled manifest, colors work perfectly! Thank you @Martin_fr and @dseligo for the help!