English words like "brunette", "blonde", and "redhead" refer to people of a particular hair color. Are there similar words in Latin? It is easy to express hair color in English or Latin with several words: "a girl with red hair", virgo crinibus rubris. I am looking for adjectives or nouns like my three English examples. I doubt that phrases like virgo rubra would be as easy to understand as "redhead", but I will be gladly proven wrong if color words can be used this way.
Color words are used in the manner you describe, and virgo rufa indeed means a redhead. For example, the L&S dictionary gives references to nuntia fulva Jovis "golden[-haired] messenger", and exactly vigro rufa in (Ter. Heaut., v., 5), where Clitipho refuses to marry rufamne illam virginem, / caesiam, sparso ore, adunco naso.
Also, there is a reason why Rufus was a common Roman surname!
I doubt ruber could be used as a hair color description, though, except maybe for special effect. The adjective refers to the color of blood, setting sun and red paint, and may be understood in many contexts as scarlet, crimson or ruby red. You would rather describe in such a way someone who dyed their hair (bold) red, as opposed to the naturally occurring red hair.
ADDEDNUM: I found a reference to ruber signifying a hair color in (Mart. XII., 54):
crine ruber, niger ore, brevis pede, lumine laesus,
rem magnam praestas, Zoile, si bonus es.
Arguably, crinis ruber is as hyperbolic here as calling Zoile's os niger is. In my thinking, this is rather an example of the "special effect" usage that I mentioned above.
I've found that:
Dans l'introduction, l'auteur insiste sur l'écart significatif qui existe entre les catégories chromatiques de la langue latine et celles des langues occidentales modernes. Il prend l'exemple de flauus, 'blond', viridis, 'verdoyant', et caerulus, '(bleu) profond', qui renvoient à des éléments précis dont la couleur n'est que l'une des propriétés remarquables (la chevelure, les végétaux, l'eau).
The author insists on the difference in the notion of "color" for ancients and moderns, and take the example of flauus, "blond", viridis, "greenish", and caerulus, "deep" (blue), that are linked to precise elements, for which the color is only one of the remarkable properties (respectively here, the hair, the grass, the water)
From: http://bmcr.brynmawr.edu/2010/2010-09-17.html, by Adeline Grand-Clément.
So, according to this paper, there was no "brunettes" or "blond". And they didn't consider the color names as we do, in modern societies.
In English, those words are from old French brune/brun/brunette, and blond, they are late words (I'll add the date they entered in the French language if you are interested), so they came in English even later. they weren't genuinely used for hair colour in old French. "Brun" means something that is brown, etc...
For "Rufus", it's a surname, and it can mean "red-haired" according to Lewis & Short
"rufus quidam": redhaired, red-headed, Plaut.
, but it can mean any other red things that the man called "Rufus" had. Maybe he was dark-haired with a reddish beard, or had always a red mantel, or anything.
The Spanish dictionary Valbuena gives "bermejo" as one of the meanings, it means "of reddish complexion".
Colours had also probably connotations like it is in modern languages, for instance, when you say "Mary the red", meaning someone who is cruel and bloody. So, it's a difficult matter. There are books about colors connotations in ancient languages, it would require us to read them to answer the question about connotations.