How many types of blue are there in the nature ?

Answer 1

All color perception is a matter of human psychology and culture. Different people will see colors differently and people from different cultures will too The number of "shades" of a "color" is completely arbitrary (more or less).

Answer 2

The sensation of blue is evoked by light having a spectrum dominated by energy in the wavelength range of about 440–490 nm.

Divide it up any way you please.

http://en.wikipedia.org/wiki/Blue

Answer 3

None, Blue isnt a thing, its simply the way humans preceive the reflected light waves off an object.