Charles Darwin in 1878. His contemporaries assumed that his ruddy complexion in his later years was a sign of good health, but it may have been connected to his ill-health, particularly the heart disease that probably contributed to his death.
Update: This morning (18th November 2014), I received my complimentary copy of “The Readable Darwin; The Origin of Species (Chapters 1 to 8)” by Jan A. Pechenik, the cover picture of which is based on my colourisation of this photo. I won’t be getting any royalties, indeed I didn’t ask for them; being published was enough for me, and the free book was icing on the cake. Even so, and having only scanned the book and read the first chapter, I can heartily recommend it.