안녕하세요...
이렇게 하면 도움이 될려나?

        TPoint tp;
        HDC dc = GetDC(0);
        int flag=0;
        Graphics::TCanvas *ScreenCanvas = new Graphics::TCanvas;

        ScreenCanvas->Handle = dc;
        GetCursorPos(&tp);

        ScreenCanvas->Pixels[tp.x][tp.y];// 이게 색정보가 되겠죠?

        delete ScreenCanvas;
        ReleaseDC(NULL,dc);