So High Valyrian is one of those languages without an evolved colour scheme? I know that most languages go from categorizing colours in black(dark), white(shining), red(blood) to more sophisticated distinctions and languages with the same word for blue and green are usually older or not as evolved (depending on circumstances). At least in "our World".
Japanese has 青い which in most of cases means blue, but in some contexts, mostly set phrases, - green. Otherwise Japanese has all the words to describe the colours you'd expect, so I don't know if you can say it lacks an "evolved colour scheme".
I'm wondering if something similar applies to High Valyrian.