请问用gtk开发界面创建窗口，如何更改窗口的背景色和在窗口内画矩形

程序是想改窗口的背景色和画几个不同颜色的矩形，颜色是用color1赋值的
程序编译可以通过但有警告，且还画出的矩形都是一个颜色，这是怎么回事。
谢谢！


#include 
#include 
#include 

GtkWidget *window;
GdkColormap *colormap;
GdkColor color;

GdkGC *gc;


void mbg(){

if(gdk_colormap_alloc_color(colormap,&color,FALSE,TRUE)){

gdk_window_set_background(window->window, &color);

}
}

void draw(){
GdkColor color1;
gc=gdk_gc_new(window->window);

color1.red=0x0000;
color1.blue=0x0000;
color1.green=0x0000;

if(gdk_colormap_alloc_color(colormap,&color1,FALSE,TRUE))
gdk_rgb_gc_set_foreground(gc,&color1);

gdk_draw_rectangle(window->window,gc,FALSE,25,50,450,200);

color1.red=0xffff;
color1.blue=0x0000;
color1.green=0x0000;

if(gdk_colormap_alloc_color(colormap,&color1,FALSE,TRUE))
gdk_rgb_gc_set_foreground(gc,&color1);

gdk_draw_rectangle(window->window,gc,FALSE,30,55,450,200);

color1.red=0x0000;
color1.blue=0x0000;
color1.green=0x0000;

if(gdk_colormap_alloc_color(colormap,&color1,FALSE,TRUE))
gdk_rgb_gc_set_foreground(gc,&color1);

gdk_draw_rectangle(window->window,gc,FALSE,25,270,260,100);
color1.red=0x0000;
color1.blue=0xffff;
color1.green=0x0000;

if(gdk_colormap_alloc_color(colormap,&color1,FALSE,TRUE))
gdk_rgb_gc_set_foreground(gc,&color1);

gdk_draw_rectangle(window->window,gc,FALSE,30,275,260,100);

color1.red=0x0000;
color1.blue=0x0000;
color1.green=0x0000;

if(gdk_colormap_alloc_color(colormap,&color1,FALSE,TRUE))
gdk_rgb_gc_set_foreground(gc,&color1);

gdk_draw_rectangle(window->window,gc,FALSE,300,270,175,100);

color1.red=0xffff;
color1.blue=0x0000;
color1.green=0x0000;

if(gdk_colormap_alloc_color(colormap,&color1,FALSE,TRUE))
gdk_rgb_gc_set_foreground(gc,&color1);

gdk_draw_rectangle(window->window,gc,FALSE,305,275,175,100);
}

int main(int argc, char *argv[]){

gtk_init(&argc,&argv);
window=gtk_window_new(GTK_WINDOW_TOPLEVEL);
gint width=500;
gint height=400;
gtk_widget_set_usize(window,width,height);
color.red=0;
color.blue=0;
color.green=0;

colormap=gtk_widget_get_colormap(window);
gtk_signal_connect(GTK_OBJECT(window),"event",GTK_SIGNAL_FUNC(mbg),(gpointer)window);
gtk_signal_connect(GTK_OBJECT(window),"event",GTK_SIGNAL_FUNC(draw),(gpointer)window);
gtk_widget_show(window);

gtk_main();

return 0;

}