It is well known that solitons in integrable systems recover their original profiles after their mutual collisions. This is not true in the case of optical fibre arrays, governed by a set of integrable coupled nonlinear Schrodinger (CNLS) equations. We consider the Manakov- and mixed-type ‘two-component’ CNLS systems. The most important characteristics of these systems are: (1) The polarizations of the two-component solitons are changed through their mutual collisions (Manakov system) and (2) the energy (intensity) switching occurs through the head-on collision (mixed system). By placing the above solitons on the primary star graph (PSG), we see that soliton collisions give rise to interesting phase changes in PSG: (a) The transition in PSG from its depolarized state to polarized one; (b) a state with selectively amplified bond is generated on PSG from its homogeneous state. These results will be applicable to network protocols using optical fibre arrays.