If the 100 L and the 135 and all the nikons survive the heat, then this will too. "Shameless marketing" is much easier to believe.
Physics........................Physics.
The white color on most Canon lenses is really there to protect some lens' elements, except for the 70-300L where it's pure marketing.
Btw I also taped my 70-300L for reasons: a) inconspicuous when doing nature shots, the commercial lens covers are very expensive, b) looks cheaper = theft hopefully less likely, c) less embarrassing ("I'm rich! I feel pro! Bow down and step aside to make room for the photog!").