Author: Jonas Bilinkevicius

How to change the system colours

Answer:

Solve 1:
1   
2   procedure TMainForm.Button4Click(Sender: TObject);
3   var
4     nColorIndex: array[1..2] of integer;
5     nColorValue: array[1..2] of longint;
6   begin
7     nColorIndex[1] := COLOR_ACTIVECAPTION;
8     nColorIndex[2] := COLOR_BTNFACE;
9     nColorValue[1] := clBlue; {define the color you want}
10    nColorValue[2] := clRed; {in that case is the caption bar and button color}
11    SetSysColors(2, nColorIndex, nColorValue);
12    PostMessage(HWND_BROADCAST, WM_SYSCOLORCHANGE, 0, 0);
13  end;


You could have a look into the "Win32 API reference", under the "SetSysColors" 
section. There, if you directly go to "GetSysColors" you'll get alist of the places 
where you can change the colors. (e.g taskbar, borders, etc). In your case use 
COLOR_BACKGROUND and COLOR_DESKTOP.


Solve 2:
14  
15  procedure TForm1.Button1Click(Sender: TObject);
16  const
17    ColCount = 2;
18    Elements: array[0..ColCount - 1] of Integer = (COLOR_WINDOW, COLOR_WINDOWTEXT);
19    Colors: array[0..ColCount - 1] of TColorRef = (clBlue, clYellow);
20  begin
21    if not SetSysColors(ColCount, Elements[0], Colors[0]) then
22      RaiseLastWin32Error;
23  end;