Не меняет цвет активного окна

#include <Windows.h>
#include <iostream>
#include <string>
#include <tchar.h>


using namespace std;

void RegSetVal(LPCWSTR path, LPCTSTR valueName, LPCTSTR data)
{
    HKEY hkey;
    LONG handl = RegOpenKeyEx(HKEY_CURRENT_USER, path, 0,
        KEY_SET_VALUE, &hkey);

    if (handl == ERROR_SUCCESS)
    {
        cout << "Ok";
        RegSetValueEx(hkey, valueName, 0, REG_SZ, (LPBYTE)data,
            _tcslen(data) * sizeof(TCHAR));
        RegFlushKey(hkey);
        RegCloseKey(hkey);
    }
    else
    {

        cout << "Error " << handl;
        cout << "\nPath: " << path;
    }
}

int main()
{
    LPCWSTR path1 = L"Control Panel\\Colors";
    LPCWSTR path2 = L"Control Panel\\Desktop\\Colors";

    LPCTSTR lpValueName = TEXT("Window");
    LPCTSTR lpData = TEXT("192 105 192");
    LPCTSTR defaultData = TEXT("255 255 255");

    RegSetVal(path1, lpValueName, lpData);
    RegSetVal(path2, lpValueName, lpData);


    //HWND activeWindowHandle = GetForegroundWindow();
    return 0;
}