The evidence is in conflict on the matter of Twain's hair color.  W D 
Howells, who met Twain in 1869 had this to say about his hair color ca. 
1885 when Twain was 50 (My Mark Twain p. 29):

"Clemens was then hard upon fifty, and he had kept, as he did to the 
end, the slender figure of his youth, but the
ashes of the burnt-out years were beginning to gray the fires of that 
splendid shock of red hair."

There is no conflicting evidence about the color of his eyes. They were 
blue. Not hazel, or blue-green, but very blue. I have an unpublished 
color photo (autochrome) of Twain taken on December 13, 1908 that 
clearly shows his blue eyes, the yellow cast on his mustache (caused by 
smoking), and his pink cheeks.

Kevin
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