Pith Helmet, European Colonial Powers

However, the pith helmet was used by all European colonial powers, and during the 1880s even by the United States Army [2] in the south west. It was commonly worn by white officers commanding locally recruited soldiers in the colonial troops of France, Britain, Spain, Portugal, Italy, Imperial Germany and the Netherlands, as well as civilian officials in their tropical territories. White troops serving in the tropics usually wore pith helmets, although on active service they were sometimes replaced by more comfortable and less conspicuous alternatives such as the wide brimmed slouch hats worn by US troops in the Philippines and by British Empire forces in the later stages of the Boer War.

Source: Wikipedia > Pith Helmet