Bluebells are a kind of flower in English. (The famous Bluebell steam railway is named after them). Is this the same in Polish?
I am not good at flowers, but I think not. My little google and wikipedia reaserch tells me we have specific botanic names for all of flowers that can be called bluebells in English.
We call some flowers dzwonki (small bells) and dzwoneczki (little small bells) and some variants, and when they are blue we call them niebieskie dzwonki, but it is just bells that are blue, not some set expression.