Lord Tyrion Lannister from "A Song of Ice and Fire".
Alias: The Imp, Halfman, Giant of Lannister, Yollo, Hugor Hill
Title: Hand of the King (former), Master of Coin (former), Lord of Casterly Rock (by birth)
Allegiance : Second Sons, House Lannister
Born: In 274AL, at Casterly Rock
Spouse: Tysha, 1st (annulled), Sansa Stark, 2nd
The portrait is made by Roman Papsuev also known as "Amok".
He generously allowed me to upload his awesome portraits here and represent him on deviantART.
You can find more portraits of him in my gallery -->
[link]Tyrion Lannister & "A Song of Ice and Fire" © George R. R. Martin
The portrait © Roman Papsuev alias "Amok"
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But there is one problem....Tryion in aSoIaF had hair both black and golden...in a mixed way
just some black hair between his significantly more golden hair...
if you see him from distance and not check each hair of him individually you will see a darker golden color...
look at jaime or cerseis hair and compare them with tyrions...
his hair is not as golden as their hair because of the black hair between his golden hair make it "darker"!
but your description seems more valid.