Put Shield Control GUI textures here:

background.png - full GUI background, 330x208
button_rect.png - rectangular buttons, any size used by the GUI will be stretched
button_square.png - upgrade slots and square buttons, 20x20 recommended
color_button.png - special effect color button, 28x28 recommended
text_field.png - trusted player name text box, 118x20 recommended

Textures can be white/gray; the current shield effect color swatch is drawn by code.
