Lowest bit of rand in Windows:
#pragma comment(linker, "/defaultlib:user32")
#pragma comment(linker, "/defaultlib:gdi32")
#pragma optimize("gt", on)
#include <windows.h>
#include <stdlib.h>

static struct {
DWORD* pData{};
HWND hwnd{};
HDC hdc{};
const int w = GetSystemMetrics(SM_CXSCREEN);
const int h = GetSystemMetrics(SM_CYSCREEN);
} Screen;

static void paint() {
HDC hdc = GetDC(Screen.hwnd);
BitBlt(hdc, 0, 0, Screen.w, Screen.h, Screen.hdc, 0, 0, SRCCOPY);
ReleaseDC(Screen.hwnd, hdc);
}

static void draw() {
for (int i = 0; i < Screen.w * Screen.h; ++i)
Screen.pData[i] = (rand() & 1u) * 0xFFD050;
}

static LRESULT WINAPI MsgProc(HWND hWnd, UINT msg, WPARAM wPar, LPARAM lPar) {
switch (msg) {
case WM_PAINT:
paint();
break;
case WM_KEYDOWN:
switch (wPar) {
case VK_SPACE:
draw(), paint();
break;
case VK_ESCAPE:
return PostQuitMessage(0), 0;
}
break;
case WM_DESTROY:
return PostQuitMessage(0), 0;
}
return DefWindowProc(hWnd, msg, wPar, lPar);
}

int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int) {
WNDCLASSEX w{};
w.cbSize = sizeof(w);
w.hCursor = LoadCursor(0, IDC_ARROW);
w.lpfnWndProc = MsgProc;
w.lpszClassName = "w";
RegisterClassEx(&w);

BITMAPINFO bi{};
auto& h = bi.bmiHeader;
h.biSize = sizeof(h), h.biCompression = BI_RGB; h.biBitCount = 32,
h.biPlanes = 1; h.biHeight = -Screen.h, h.biWidth = Screen.w;
HDC dc = GetDC(0);
Screen.hdc = CreateCompatibleDC(dc);
SelectObject(Screen.hdc, CreateDIBSection(dc, &bi,
DIB_RGB_COLORS, (void**)&Screen.pData, 0, 0));

draw();

Screen.hwnd = CreateWindowA("w", "", WS_POPUP, 0, 0,
Screen.w, Screen.h, GetDesktopWindow(), 0, 0, 0);
ShowWindow(Screen.hwnd, SW_MAXIMIZE);

for (MSG m; GetMessage(&m, 0, 0, 0) > 0; DispatchMessage(&m));
}