What kind of paint did they use to paint the Eiffel tower?
The Eiffel Tower has been painted in a number of different
colors throughout its history, but today, it is painted a color
called "Eiffel Tower brown," which turns out to be the color of
milk chocolate, and it is used in three very slightly different
shades at different elevations of the tower (higher elevations use
a lighter shade), in order to accentuate the impression of height.
The paint is synthetic, lead-free, and silicone-based, and the
entire structure is repainted over a period of 6-7 years by several
dozen fearless and highly acrobatic painters, by hand (no automated
way of painting the tower has ever been satisfactory). The most
recent repainting operation (the nineteenth) began in 2009 and
required about two years.