button background color in gtk3

[Rudra Banerjee <bnrj rudra yahoo com>]

Friends, 
I am putting gtkbuttons inside a grid with modify_bg. I am getting an
odd case that when the window is focused, all buttons are showing white,
not what suggested by modify_bg. The same structure was working fine in
gtk2 (while I was using table instead of grid).
I am posting the complete minimal code(60 line only) for your reference.

I have seen that the gtk_widget_modify_bg is deprecated in gtk 3 so I
tried the suggested method with gtk_widget_override_background_color but
there it seems that declaration of GdkColor colorRed2 = {0x0000, 65535,
29555, 24158} has changed to something like GdkRGBA.
I tried to change to

GdkRGBA colorRed = {1,0,0,1};
yeilding error:

âconst struct GdkRGBA *â but argument is of type âGdkRGBAâ

Please Help.
here is the complete code:

#include <gtk/gtk.h>
int main(int argc,
        char *argv[]) {
    GtkWidget *window;
    GtkWidget *grid;
    GtkWidget *menubar;
    GtkWidget *filemenu;
    GtkWidget *quit;
    GtkAccelGroup *accel_group = NULL;

    gtk_init(&argc, &argv);
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window), "Try Grid");
    gtk_container_set_border_width(GTK_CONTAINER(window), 05);

    grid = gtk_grid_new();
    gtk_container_add(GTK_CONTAINER(window), grid);
 gtk_grid_set_column_homogeneous(GTK_GRID(grid),TRUE);
 gtk_grid_set_row_homogeneous(GTK_GRID(grid),TRUE);
    menubar = gtk_menu_bar_new();
    filemenu = gtk_menu_new();

    accel_group = gtk_accel_group_new();
    gtk_window_add_accel_group(GTK_WINDOW(window), accel_group);

    GtkWidget *file = gtk_menu_item_new_with_mnemonic("_File");
    quit = gtk_image_menu_item_new_from_stock(GTK_STOCK_QUIT,
accel_group);

    gtk_menu_item_set_submenu(GTK_MENU_ITEM(file), filemenu);
    gtk_menu_shell_append(GTK_MENU_SHELL(filemenu), quit);
    gtk_menu_shell_append(GTK_MENU_SHELL(menubar), file);

    g_signal_connect(G_OBJECT(quit), "activate",
G_CALLBACK(gtk_main_quit), NULL);

    gtk_grid_attach(GTK_GRID(grid), menubar, 0, 0, 2, 1);


    /* Color Scheme */
    GdkColor colorRed2 = {0x0000, 65535, 29555, 24158};
    GdkColor colorBlue = {0x0000, 3598, 57054, 61937};
    GdkColor colorWht = {0x0000, 65535, 65535, 65535};


    GtkWidget *Abutton = gtk_button_new_with_label("A");
    gtk_grid_attach(GTK_GRID(grid), Abutton, 0, 1, 1, 1);
    gtk_widget_modify_bg(Abutton, GTK_STATE_NORMAL, &colorBlue);
    gtk_widget_modify_bg(Abutton, GTK_STATE_PRELIGHT, &colorWht);

    /* Create second button */
    GtkWidget *Bbutton = gtk_button_new_with_label("B");
    gtk_grid_attach(GTK_GRID(grid), Bbutton, 10, 1, 1, 1);
    gtk_widget_modify_bg(Bbutton, GTK_STATE_NORMAL, &colorRed2);
    gtk_widget_modify_bg(Bbutton, GTK_STATE_PRELIGHT, &colorWht);


    gtk_widget_show_all(window);
    gtk_main();

    return 0;
}