Yes, I’m aware that in any language there are many words to signify different shades of different colors. I’m not trying to make the point that there are no words in English for light shade of blue and that Russian is somehow superior.

You won’t see stuff like “aquamarine” or “cerulean” in A1 English textbook though, as these are complex words not even all native speakers use. Cyan is a possible candidate, but most likely in colors section only “Blue” will be represented. That is my personal experience though.

In Russian, a word for “light blue” is a very common color that is referenced all the time alongside “blue”, children knowing it from very young age. My point is different cultures have different sets of commonly operated colors, not words for colors overall.

This creates curious confusions, just now I’ve looked for translations between RU and ENG, and in different sources “Blue” is translated both as “Синий” (darker blue) and “Голубой” (lighter blue).