Ultimate Devo F12E (devof12e-XMS) builds

void _gui_draw_background(int x, int y, int w, int h)
{
#ifdef _DEVO12_XMS_TARGET_H_
    if(y + h < 32) {
        LCD_FillRect(x, y, w, h, RGB888_to_RGB565(0x80, 0x80, 0x80));
    } else if(y >= 32) {
        LCD_FillRect(x, y, w, h, RGB888_to_RGB565(0x90, 0xc0, 0xe0));
    } else {
        LCD_FillRect(x, y, w, h, RGB888_to_RGB565(0x90, 0xc0, 0xe0));        
        LCD_FillRect(x, y, w, 32 - y, RGB888_to_RGB565(0x80, 0x80, 0x80));
    }
#else
    LCD_DrawWindowedImageFromFile(x, y, "media/backgrnd" IMG_EXT, w, h, x, y);
#endif
}

[background]
  drawn_background=1
  bg_color=90C0E0
  hd_color=808080

You can select to draw background instead a background image for color GUI. This will greatly speed up the drawing of the pages. You can set header color and background color. The settings are in "config.ini" file. By default used background image.

[background]
  drawn_background=0
  bg_color=50A0D8
  hd_color=707070