Size of dispersed phase particles in colloid? I am really confused about what the size of particles of dispersed phase in a colloid is: one of my textbook says its between $1 - 100nm$, another says its between $1-1000nm$, and Wikipedia says its between $2-500nm$. Is there any reliable source giving the exact information?
Its between $1-1000nm$ as stated on wikipedia in a paragraph name IUPAC definition.



  Colloid: Short synonym for colloidal system.
  Note: Quotation from refs.[3][4]
  Colloidal: State of subdivision such that the molecules or polymolecular particles dispersed in a medium have at least one dimension between approximately 1 nm and 1 μm, or that in a system discontinuities are found at distances of that order.[5]
  Note: Quotation from refs. [3],[4]


Edit: Since it is mention under IUPAC definition that size lies between $1nm-1000nm$, therefore this must be the correct size.