Color Problems

[Duncan Perrett elekta com]

Hello,

I am struggling with colors.  Why does my window show up as bright blue
instead of grey?
I want to use grey colors and a GdkImage.
I know that grey is obtained if the rgb values are all equal.
My XServer has a depth of 24 bits.
My application creates a GdkImage from the default visual.

the bytes per line returned is 4096
the bits per pixel returned is 32
the bytes per pixel returned is 4
the byte order enum value is 0

the cgrey0 pixel value is 0
the cgrey1 pixel value is 3289650   (32 32 32 in hex)
the cgrey2 pixel value is 8224125   (7D 7D 7D in hex)

I was assuming from this that the rgb format was :-

MSB aaaa aaaa rrrr rrrr gggg gggg bbbb bbbb LSB

Annoyingly the grey color I attempt to draw shows up bright blue!!!

I have created a colormap and allocated 3 or 4 colors to it using :-

    m_refVisual = Gdk::Visual::get_system(); // get system's default visual
for default GDK screen
    m_refGdkImage = Gdk::Image::create(Gdk::IMAGE_FASTEST, m_refVisual,
m_XRes, m_YRes);
    char* pImage = (char*)(m_refGdkImage->get_mem());
    guint16 bytesPerLine = m_refGdkImage->get_bpl();
    guint16 bytesPerPixel = m_refGdkImage->get_bpp();
    std::cout << "bytes per line, bpl=" << bytesPerLine << std::endl;
    std::cout << "bits per pixel, bpp=" <<
m_refGdkImage->get_bits_per_pixel() << std::endl;
    std::cout << "bytes per pixel, bpp=" << bytesPerPixel << std::endl;
    std::cout << "byte order=" << m_refGdkImage->get_byte_order() <<
std::endl;

//create grayscale colormap for default system visual...
    windowColormap = Gdk::Colormap::create(m_refVisual,true);
    //create several grey colors
    Gdk::Color cGrey0;
    cGrey0.set_grey(0);

    Gdk::Color cGrey1;
    cGrey1.set_grey(12800);

    Gdk::Color cGrey2;
    cGrey2.set_grey(32000);

    Gdk::Color cGrey3;
    cGrey3.set_grey(64000);

    //allocate grayscale values to colormap
    bool allocSuccess = windowColormap->alloc_color(cGrey0);//, true,
true);
    allocSuccess = windowColormap->alloc_color(cGrey1);//, true, true);
    allocSuccess = windowColormap->alloc_color(cGrey2);//, true, true);

    m_cGrey0PixelVal = cGrey0.get_pixel();
    std::cout << "cGrey0 Pixel Value = " << m_cGrey0PixelVal << std::endl;
    m_cGrey1PixelVal = cGrey1.get_pixel();
    std::cout << "cGrey1 Pixel Value = " << m_cGrey1PixelVal << std::endl;
    m_cGrey2PixelVal = cGrey2.get_pixel();
    std::cout << "cGrey2 Pixel Value = " << m_cGrey2PixelVal << std::endl;

    m_refGdkImage->set_colormap(windowColormap);

    for (int y=0; y<m_YRes; y++)
    {
        for (int x=0; x<m_XRes; x++)
        {
            pImage[(y*bytesPerLine)+(x*bytesPerPixel)] =
m_MlcGrey2PixelVal;
        }
    }

    window->draw_image(m_refGC, m_refGdkImage, 0, 0, 0, 0, -1, -1);




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