The Eiffel Tower is known nowadays to be a dark brown (multiple different shades, in fact!) however it didn't start out that way! In 1887/88, Venetian Red was applied to the structure in the workshop pre-assembly. 1889 saw a darker red applied, which stayed until 1892 when it got painted an ochre brown. In 1899, 5 different shades were applied from the base (yellow-orange) to the top (light yellow).

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The Eiffel Tower was only meant to be a temporary exhibit for the World's Fair in 1889 for 20 years. 1898 saw Eiffel attempt to find a justification to keep it. He offered it up to two engineers to experiment with wireless transmissions. While not enough to save it, in 1904 it was equipped with an antennae that allowed communication between the French Army and their defense posts almost 300 miles away. 1909 saw the Eiffel Tower's lease renewed for 70 more years wherein it ushered the Age of the Radio and aided in two World Wars which solidified it in the French Identity.

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Many artists absolutely despised the Eiffel Tower when it was first built including Guy de Maupassant and Alexandre Dumas Jr. (son of the famous Alexandre Dumas, author of the Three Musketeers). Political cartoons were made of Gustave Eiffel as well as lengthy denouncements in papers from Paul Verlaine who called it a "belfry skeleton", François Coppée who said it was a "mast of iron gymnasium apparatus, incomplete, confused and deformed", Guy de Maupassant who went onto write "this high and skinny pyramid of iron ladders, this giant ungainly skeleton upon a base that looks built to carry a colossal monument of Cyclops, but which just peters out into a ridiculous thin shape like a factory chimney." and Joris-Karl Huysmans who stated it resembled "a hole-riddled suppository".

Sources: This YouTube video that I got sucked into this morning and the Eiffel Tower Website xD