The first three images google gave me for "kindergarten colors":
http://3.bp.blogspot.com/_kkd-_JfiGWA/TUdXevHfRUI/AAAAAAAAAb...
https://s-media-cache-ak0.pinimg.com/736x/fe/a8/da/fea8dad8f...
In Russian, sky blue is a distinct rainbow color from blue, but pink is not.
In English, blue and indigo are treated as distinct colors, but this is more tradition than perception (so as to pad the number to the requisite 7).
If you compare the typical representation of the rainbow, you'll see that it has the corresponding difference. Russian depiction of rainbow has pure medium-dark blue between sky blue and violet, and violet is dark:
http://nobacks.com/wp-content/uploads/2014/11/Rainbow-26.png
(Note that blue in this pic is about as dark as it gets; quite often it's actually lighter - usually, sky blue and blue are closer together than blue and violet.)
English depiction of rainbow has some kind of really dark blue with a strong hint of violet in the same place, and violet is brighter:
I think this is really similar to the two blues in Russian. Interestingly, while I grew up speaking Russian, I learned English at a young-enough age that I actually find the distinction between the two blues a bit confusing at time—I know about it, obviously, but it actually feels less strong than the distinction between red and pink. But that's just me with my weird upbringing :).
In English we have blue and cyan, but the word cyan is rarely used except to distinguish from blue.