I am not sure what is your question. May be you ask the difference between azzurro and blu. In English there is only one woed. In Italian we distinguish two colours: azzurro is the colour of the sky, of eyes, of the calm sea ; it is a light blu.
Blu is the icon of the internet (e); to give you some samples, you can also find blu in the flag of Finland, as well as in other national flags (Icaeland, UK...). I suggest you to look for the flag of Fiji, because this has both colours - I think you can easily understand what is azzurro and what is blu.