class WorkingBoots_ColorBase extends Shoes_Base {};
class WorkingBoots_Grey extends WorkingBoots_ColorBase {};
class WorkingBoots_Brown extends WorkingBoots_ColorBase {};
class WorkingBoots_Green extends WorkingBoots_ColorBase {};
class WorkingBoots_Yellow extends WorkingBoots_ColorBase {};
class WorkingBoots_Beige extends WorkingBoots_ColorBase {};