QUOTE
The idea of blue and green not being separated as two different colors was hard for me to accept at first, but being an artist, I understand that there is very little difference between some of the varying shades of blue as it turns to green.
what was more difficult was the idea that either green or blue could be also concidered black. Until I began to think about how sometimes black will give off a blue shine. There are some blues and greens like the deep forest green that can look black unless contrasted by a true black right next to it.
I've read that the Navajo language does not distinguish between blue and green, but uses the same word for both. I think the Chinese language is a different case, though. I looked up the character
綠 on that very useful site you linked to, and it appears it's been around since the oracle bone days. I'm not entirely certain that it meant "green" back then, but it seems to have been the case. On the other hand,
藍 is a bit more recent, and no doubt originally referred to the indigo plant, rather than the color. Nevertheless, it seems Chinese has long had at least two words that could be translated as "green", unlike (supposedly) the Navajo language. And English has words like "turquoise" and "aquamarine" that could be used to describe the sea or the sky, although they are never used to describe green vegetables or black cloth.
But there's really no reason to expect a one-to-one correspondence between color names in any two languages. Even in English, if you go back far enough, you'll find that the classification of colors used to be quite a bit different from what it is today. Many color names commonly used in contemporary English were borrowed from other languages, and it seems people in some industries are compelled to invent new colors (usually with compound names, though) all the time.
QUOTE
Surviving textual descriptions or artistic representations of Liao, Song, and Western Xia uniforms show that these were coloured differently according to unit and rank, and not standardized according to the phase representing the regime.
I had suspected that the uniform colors for the different states were for the benefit of a modern audience, but I wasn't entirely certain of that, which is why I my interest was piqued when I found this thread.
QUOTE
That is not to say that flags and ceremonial court dress would not still reflect the colour of a regime. However we have no visual evidence to prove this either way - only evidence from written records.
I assume a Chinese state's color was more than just an abstract symbol. You say the written evidence indicates it was probably used in flags and ceremonial court dress. Are there other areas where it was recorded to have been used?
QUOTE
Ran Min's colour is not known, but since Later Zhao used the colour black, it makes sense that he would use blue.
Which colour Later Yan and Western Yan used would depend on whether they accepted Former Qin as legitimate. If they did, they would use red rather than reverting to the Former Yan colour of blue. Southern Yan saw itself as a continuation of Later Yan, so it would not have changed its colour. Northern Yan would use yellow if Later Yan used red.
Thanks for the information, Yun.

I think I have it all figured out now (at least, for Yan and their neighbors):
Jin - white (but its ruling house preferred red)
Han - red (claiming to be a continuation of the original Han state)
Former Zhao - black (claiming to be the successor to Western Jin)
Later Zhao - black (claiming to be the successor to Western Jin)
Former Yan - black (claiming to be the successor to Western Jin) until the mid-360s, then blue (claiming to be the successor to Later Zhao)
(Ran) Wei - probably blue (claiming to be the successor to Later Zhao)
Former Qin - blue (claiming to be the successor to Later Zhao)
Later Qin - red (claiming to be the successor to Former Qin)
Western Yan - either blue (claiming to be a continuation of Former Yan) or red (claiming to be the successor to Former Qin)
Later Yan - either blue (claiming to be a continuation of Former Yan) or red (claiming to be the successor to Former Qin)
Southern Yan - either blue or red (claiming to be a continuation of Later Yan)
Northern Yan - either red or yellow (claiming to be the successor to Later Yan)
Do you suppose the possible red color of either Later or Northern Yan (or even Later Qin) would have influenced Northern Wei's initial decision to use yellow as its color, apart from the supposed connection to Huangdi?
I have some questions about uniform colors as well, but since those didn't depend on regime colors (at least in the Age of Fragmentation), perhaps I should start a thread on that somewhere else, if one doesn't exist already. (I notice there's already a thread on uniform colors, but it seems focused on the terra cotta soldiers.)