Colors are often easily-translated concepts from language to language. Occasionally, especially when two languages are very far apart geographically or culturally, there may be a case where the color spectrum isn't divided up in exactly the same way. Another noder has written about this problem in Chinese.
Russian, which is by far genetically closer to English, German, Spanish, and other Indo-European languages, for the most part has a one-for-one translation for each color, except blue. There is no simple word for 'blue' in Russian. There are the two distinct colors: sinii (cиний) and goluboy (гoлyбoй).
Sinii is a dark blue, sometimes royal blue, and a better general term for blue if you're in some way hard-pressed for a single word. Goluboy is used more to describe a pale blue, sky blue baby blue, even a light blue-green. The main difference is that one is deep and bold whereas the other is usually pale and weak. But in Russian they are treated as two separate colors, not like how German has blau and hellblau (the latter is a form of the former), but actually two different colors. In the same way, English 'pink' refers to a shade of red, but goluboy is not necessarily a shade of sinii, and there is no simple neutral 'blue.' It would almost be like if English only had 'crimson' and 'pink,' but not 'red.'
Also, curiously, for some reason this is how Russian slang denotes qualities of 'gay' or 'straight.' To say someone is goluboy is to call them gay.
In Czech, a close relative of Russian, there is only one word for 'blue,' (modrý) though they in fact have two words for red: červený and rudý