What hair color did Évariste Galois have?

Question

There is one historic black and white portrait of Évariste Galois that is often used [1]. However there are a number of more recent colorful portraits that imagine him to be anything from straw blond[2], things in between[3], brown[4] and black[5].

Is there any historical source that describes his hair color?

Are there arguments to that would suggest that in [1] his hair is not only black because of the medium such as that other hair colors like brown and blond were historically portrayed differently in that medium?

A sourced answer to any of these two questions would suffice. If there is indirect information (such as the color of the hair of his parent is verifiable to a similar standard of proof as asked for above) that is welcome too.

I am aware that modern recoloration are not a reliable source but the variety of hair color he is portrayed with suggests this fact is not know or easily googleable.

[1] https://commons.wikimedia.org/wiki/File:Evariste_galois.jpg

[2] https://www.deviantart.com/selunec/art/Evariste-Galois-189586719

[3] https://pl.mathigon.org/timeline/galois or https://www.deviantart.com/autumn-sacura/art/Evariste-Galois-168556089

[4] https://fineartamerica.com/featured/evariste-galois-granger.html?product=yoga-mat (this seems to be an coloration of [5]) or https://www.deviantart.com/daga-ra/art/Evariste-Galois-283582290

[5] https://www.alamy.de/stockfoto-evariste-galois-1811-1832-franzosischer-mathematiker-leider-starb-er-in-einem-duell-im-alter-von-20-jahren-datum-1832-105254851.html (again a black and white picture in a different style) or https://www.assignmentpoint.com/arts/biography/biography-of-evariste-galois.html

Answer 1

Galois was imprisoned twice, at Sainte-Pélagie prison in 1831 and at La Force prison in 1832. The prison records are apparently retained in French archives.

His prison record from Sainte-Pélagie is reproduced (as text only) in the following article, a scan of which is available from NUMDAM:

P. Dupuy, "La vie d’Évariste Galois", Annales scientifiques de l’É.N.S. 3e série, tome 13 (1896), p. 197-266.

On page 264 of the article:

Cheveux ..... chatains
Sourcils .... id.

The color of his hair is described as chestnut, and the color of his eyebrows identical to the hair color. An online article shows a cropped picture of Galois's second prison record:

Olivier Courcelle, "Galois à La Force", CNRS Images des mathématiques, January 22, 2017

In the picture shown at the top of the webpage:

cheveux et sourcils chatains-bruns

Both hair and eyebrows are described as having chestnut-brown color.