By combining images taken through different filters in the visible and infrared, the MESSENGER data allow Mercury to be seen in a variety of high-resolution color views not previously possible. MESSENGER's eyes can see far beyond the color range of the human eye, and the colors seen in the accompanying image are somewhat different from what a human would see.
Bailey, D., Bailey, S. & Hufford, M. (1996) Copperheads Smell Like Cucumbers. [Audio] Retrieved from the Library of Congress, https://www.loc.gov/item/cmns001450/. Bailey, Dave, Sherman Bailey, and Mary Hufford.
Oops, forgot to say, even if its not SD issues that cause the smell, it could maybe be just an imbalance of copper. And since vitamin C often helps people with excessive copper levels, if the zinc doesn't help, maybe try vitamin C (which sometimes helps with headaches too).