Nowadays the idea of celebrating colonial fairs, where native peoples of the overseas territories could perform their ethnic habits in front on an European audience (who besides had payed for it), could seems nasty to us, disgusting or even more a crimen of slavery, but along side the 20s and the 30s of the last century, organised colonial fairs were at its hight to show to metropolitan populations and other Western country audiences, which were the benefits furnised to the natives by the Metropolitan country, and at the same time, how lucky those backward native peoples were, who thanks to their white masters, could be taken out from the darkness of the ignorance. This colonial effort, was sometimes carried out in good faith, but others it was no any other thing but looting, and greediness, a demonstration of racial imperialism and self-sufficiency, whose actors were (from the top to the bottom) governments officials, white settlers (mainly farmers), religious communities and a wide panoplia of bizarre people, such as traders, smugglers, Indiana Jones´ adventures and prodigal sons. All of them represented a vivid fresco of Western racial superiority over the colonized local people. In this paper we are going to examinate which was: 1st). the reaction of the International Community (if any) by the time those fairs were hold, and which international institutions ( remarkably the League of the Nations and the International Labour Organization) could have faced such degrading spectacle, and hence its legal tools to put an end to it, 2nd.) in a sort of contrafactual exercise, which one could be the enforceable law today, applicable by the international bodies, entitled to prosecute such crimes,and which crimes could be fitted (or penal types) into such behaviours.