The Greek that is translated as “pale green” or “pale” in English is translated in Tsafiki as “sickly yellow” which is used related to health. (Source: Bruce Moore in: Notes on Translation 1/1992, p. 1ff.)

David Clark (in The Bible Translator 2005, p. 67ff. ) says this about the translation:

“The real problem is the word chlōros in Rev 6.8. Its basic meaning is ‘green,’ and it is used to describe grass in Mark 6.39 and also in Rev 8.7. It is also used to describe vegetation in general in Rev 9.4. Does this mean that in Rev 6.8, we have a green horse? The absurdity of this has been recognized by translations from the Vulgate onwards. There the translation is pallidus, which means ‘pale.’ The Greek word chlōros can carry this meaning in some contexts, though it does not occur in this sense anywhere else in the New Testament. This is, however, the sense that came into the King James Bible in English (‘a pale horse’), and has been remarkably persistent. The problem is that this appears to be describing the horse’s health rather than its color, and to be saying that the horse is not feeling very well. This is ridiculous enough, but some more recent English versions have translated as ‘pale green’, which if anything sounds even more absurd.

“Why has this word proved such a problem to translators? I suspect that it is because they have failed to grasp the simple fact mentioned at the beginning of this article that different languages divide up the spectrum differently. Thus a word whose central meaning is ‘green (like grass)’ may also cover parts of the spectrum described by other words in other languages. In classical Greek, chlōros is used of such things as honey and egg yolk, which would never be called ‘green’ in English (unless perhaps the egg were bad!). Horses are certainly not the same color as egg yolk, but chlōros is also, and more significantly for our purposes, used to describe a mist: for this the natural color term in English would be ‘grey.’ We may therefore suggest that the part of the spectrum covered by chlōros in Greek includes what we would call ‘grey’ in English. This would not only be clear and natural, but would also strengthen the echo of the colors of the horses in Zechariah.

“In a recent conversation with a friend who is a native speaker of Welsh, I was interested to learn that Welsh divides up the spectrum in a way similar to that which I am supposing for Greek. My friend later wrote to me as follows: ‘The ‘pale horse’ in Rev 6.8 is described by the word glas (also meaning ‘blue’ in Welsh) in my older Bible, but interestingly by llwyd in a newer version. On reflection llwyd was the word 1 would have used in my boyhood for ‘grey,’ not glas. For example, my Sunday-best suit would have been llwyd.’ It seems that the old Welsh translation first published in 1588, earlier that is than the King James in English, had a more realistic approach to the color of the horse in Rev 6.8 than most English versions. And so does the newer Welsh version.

“In recent years I have also worked with two NT projects in southern Siberia — Khakas and Tuvan — where the people are interested in horses, and very familiar with them. It was an encouragement to me to study this matter further when 1 discovered that in both projects, the translator instinctively translated chlōros in Rev 6.8 by words meaning ‘grey.’ And this happened without any prompting from me!”

See also Translation commentary on Revelation 6:7 – 6:8 and complete verse (Revelation 6:8).