While pith helmets are still available for purchase online and in hat shops, they have come to symbolize white colonialist rule over the years, and, according to The Guardian, "a symbol of status -- and oppression." It's unclear if Trump was aware of the meaning, and her office has not responded to CNN's request for comment on the hat.
There is no need to wear a helmet on the type of safari Trump was taking; she was comfortably stowed in the backseat of a Toyota Land Cruiser; however, the helmet is largely used as more of a sun hat. The Secret Service agents in the vehicle were not wearing hats or helmets, and the guide seated behind her wore a uniform beret. Moreover, while there are no enforced rules or regulations for what to wear on a safari, it is widely suggested that participants avoid bright whites, reds and neon shades.