The colour blue

[Caratacus]

This is an odd one. For what it's worth, the Welsh for "blue" is 'glas' (with plural nouns, it's 'gleision'). We quite often get references to, for example "pant glas" - literally 'blue valley'. (The word for 'green' is quite different - 'gwrydd'). Obviously, we don't mean that a valley is blue! I can quite see how, at certain times of the day, a grassy valley might appear to be blue rather than green. After all, in the USA, Kentucky is referred to as "the blue-grass state"!

The only blue dye that was commonly used on textiles (so far as I am aware) was woad (indigo). This is a 'vat' dye, which is in fact insoluble in water. It has to be reduced (oxygen removed) to form a water-soluble leuco compound (and which is actually yellow) and in which the textile is soaked. On removal from the vat, atmospheric oxygen oxidises the leuco compound back to the insoluble form, which is precipitated within the fibres of the cloth. The resulting indigo-dyed material falls within the blue/green part of the colour spectrum, i.e. the indigo has a distinct green tinge to it. Obviously, woad is a very common and well-known plant which has been known to produce a dyestuff for several thousand years. Until comparatively recently it was a major crop in India, until artificial indigo came along as a result of the 'coal-tar' industry in the mid 19th century.

The question is: "do we all see the same colour". The answer is probably that we do not. Believe me, as someone who once worked as a colour chemist for Kodak, trying to get members of the public to match colours to standards was almost impossible. Virtually everyone saw a different colour - and it was never the one that our instruments said was the closest! Each colour is also affected by the other colours surrounding it, further complicating the issue.

Mike Thomas
(Caratacus)

[Nathan Ross]

the dark blue as we intend today was well known in roman times as "indacus", but somehow considered more barbaric or not fashion because of it's darkness.

I've just noticed this point. Sounds interesting - do you have a source or reference for it?

[Michael Kerr]

Pliny mentions the word Indicum in his Natural History book 35 when describing pigments and dyes. In my English translation it means Indigo which originated in India in the ancient world.


[attachment=12001]Indian_indigo_dye_lump.jpg[/attachment]
"Indian indigo dye lump" by Photo by Evan Izer (Palladian) - Own work. Licensed under CC BY-SA 2.5 via Wikimedia Commons

Regards
Michael Kerr

[Doc]

Woad and Indigo are different colors. The former produces a dark to light blue whereas indigo just makes dark blues.

I have a sagum dyed in woad and the color is like a sky blue but I have my ptyerges fringe dyed in woad and its dark blue.

With respect to dark colors.....that is an interesting point but we should also remember that darker colors were also more expensive because it required over dyeing the material. I have a paludamentum that is a rich dark red.....

When Clair Marshall made my garments, she did extensive study for my garments including having discussion with Mr. Sumner and referencing his book.

I am not suggesting that my reconstructions are perfect or the lead example BUT I think we should really be careful about running around saying dark is not proper or that light is correct.

I am an oil painter and will tell you that a common misconception of the night sky is that when painting it, black should be used. In reality, the night sky is indigo and under certain light, it can look black. So this comment can explain why a dark blue was not appealing to the Romans if we go with what Luca mentioned. When adding white to the indigo, it becomes some sort of blue/gray color.

So, how dark are we talking about..........unless we can categorically know the exact shade of a certain color.......we can debate interpretations forever.

Certain purples are so dark, the can look black-like under certain light. Case in point, the modern oil color Dioxazine purple. If put on a palette and viewed even in light from above, it looks black. Its only when you smear it onto the palette that you see its something else.

[Caratacus]

It would be interesting to see if anyone has done a proper chemical analysis of both woad and indigo. Yes, they are different colours but is this simply a concentration effect, or a genuine different chemical mixture/structure? After all, it takes only a couple of bromine atoms to turn indigo into Tyrian purple. It would be interesting to know whether 'natural' indigo is a single pure compound or a mixture of several structures with slightly different substitution patterns. I would think that the synthetic indigo is probably a single isomer. However, lacking easy access to a chemistry departmental library these days, there is no easy way for me to check.

Mike Thomas
(Caratacus)

[Doc]

Hello Mike,

I am a synthetic organic chemist and the discussion on color is always fascinating. I was reading the link below and they mentioned that indigo is derived from the woad plant but the color indigo is not directly obtained. It turns out that the leaves contain the compounds necessary for indigo to be produced outside of the plant. So it appears that the leaves must be ground and the active components isolated.
http://www.woad-inc.co.uk/dyeing_with_woad.html

Then, there is this other link that mentions woad being its own plant and that there is another plant that makes indigo but in the end, they are the same thing...

http://www.botgard.ucla.edu/html/botanyt...ny/Isatis/

[Gaius Julius Caesar]

I did see a program where they were dying with woad. Crushing the leaves to start with, then adding urine to kick it off... The darkness of the colour was down to how long the fabric was left in the concoction. Interesting to watch.

[Luca]

"do you have a source or reference for it?"
Yes, please check Michel Pastoureau - "Bleu: l’histoire d’une couleur,"

IMO dark blue, I mean a color that is really dark and in low light condition can be perceived as black, is an error in roman reenacting. But I can change my opinion of course.
In most of the examples from frescoes and mosaics I don't remember the "dark blue" color. Ok, in 1700-2500 years colours could be also chemically modified (as happened for pompeian red that in some cases it was yellow), but this is my "simple" observation. So I try to work this way.
Also I am supported by some authors such as Pastoureau.

In my "little" research of course I considered Vegetius that says that seamen were wearing tunics colored with indigo, but we are talking about IV century AD. So we cannot say romans didn't use it 100% also because Pliny describes very well how to produce it.

In our way to reenact, we don't consider historic exceptions, unique findings, ecc. We try to show the most common and the most probable reality.
Hopefully

[Nathan Ross]

Michel Pastoureau - "Bleu: l’histoire d’une couleur,"

Thanks. I can't find a copy of this book, but I have located a few references to it online. From what I can tell, Pastoureau doesn't seem to say anything about dark blue in particular, just blue in general. And from some of the quotes I've seen, I don't rate his scholarship all that highly! This is from one review:

"Whereas P. concludes that the absence of blue in the historical sources did not, as older generations of scholars would have it, mean that their physiological apparatus differed from ours, his conclusion that "social and ideological" factors were responsible is, in my view, no less shortsighted. In his account, the Greeks and Romans simply did not like blue: they were "indifferent to it -- if not downright hostile" (26). P. cites as evidence the horrified descriptions by Pliny, Caesar, and Tacitus of Germanic tribesmen covering their bodies and hair with woad before battle -- as if it were the hue that was offensive to the Roman commentators, and not the threatening behavior of the barbarian enemies."

Source

This seems pretty sloppy to me - there's no mention in Pliny, Tacitus or Caesar of 'Germanic tribesmen' (or anybody else) painting themselves with woad! Caesar mentions the Britons dying their bodies 'caerulean', and Pliny refers to some sort of plant used as body-paint in Gallic religious rituals; blue is not mentioned. None mention woad in this connection.

In most of the examples from frescoes and mosaics I don't remember the "dark blue" color.

It does seem to be uncommon as a clothing colour in Roman art, compared to red, white and yellow, but not unknown. Here are a few examples of darker blue clothing:

Woman in dark blue, playing a kithara

A woman's dress from Egypt

Army officers from Luxor

Soldier (?) in a dark blue cloak, from Fayum

Men at a bakery, from Pompeii

Woman's clothing and helmet crest

Fullery workers (slaves?) from Pompeii

A Christian priest or worshipper

Some of the paintings may have been discoloured, by time or photography, but I think that's enough to suggest that darker blues were used in clothing. The colour is also used as a background in many scenes.

And, of course, we have the famous chariot racing faction that I mentioned before, which should prove that blue generally had no 'negative' connotations!

[Alanus]

Being an ignorant barbarian, I'm probably wrong-- BUT I always thought that blue (I would suppose a dark or medium blue) was a common color within the Roman Navy (or [i]Noivy if you're speaking in Cockney[/i]). If blue was so "low-life," what does the color say about the average Roman sailor? Perhaps it was a bad dream, or maybe it was Graham Sumner's bad dream, but the whole thing is giving me the blues. :dizzy:

Oh, yes. I was in the Noivy and wore a set of very dark "blues." In the U.S. Navy, "blues" were only worn for dress occasions. I wore "Dress Blues" when shaking hands with the King of Norway. If tradition is somewhat traditional, blue was and is a formal color, and hypothetical statements by antiquarian "experts" on Roman antiquity could be full of sh**t... or the King of Norway had bad taste. ;-)

[Renatus]

(or [i]Noivy if you're speaking in Cockney[/i])

There speaks an American who seems to have learned his Cockney from Dick Van Dyke. 'N-eye-vy' would be nearer the mark.

[Alanus]

Thanks for the correction. Cockney aside, I was trying to make a point that darker blue colors probably had a higher status than interpreted earlier in this thread. :-)

[Luca]

Thanks Nathan for the images, very interesting and never seen before.

Let my specify that all what I have read about blue, mentions that blue started to be used in common dressing at the end of the first century. One point to dark blue was done by Caligula itself if my mind remembers correctly, and we are speaking about first half of the first century.
The growing importance of blu seems connected to the barbarian influences that started be relevant in the second century AD.

Said this we should consider the period of all the images Nathan reported, and I agree that we should consider that after 1900 years color can appear completely different, so we would need a chemical analysis to be 100% sure.
If a yellow pigment can revert to red (http://www.romanhideout.com/News/2011/20110922.asp) could a light colour became darker? Probably yes, but I have no proofs of course.
I remember in fact that very often purple pigment can be oxidized to black and I suspect is the case in the first image you posted as example. But again I have no proofs, sorry.

About the use of blue in the navy, as mentioned before, it is stated by Vegetius that lived in the IV century AD, I suppose in that time dark blue was widely used by romans not only in the navy.