Answer briefly:
$(a)$ How do you perceive the colour of an object?
$(b)$ Which part of our body helps us in maintaining the body balance?
$(c)$ How does the eye regulate the amount of light that falls on the retina?

(N/A) The cone cells are responsible for colour vision. There are three types of cone cells that respond to green,blue,and red light. These cells are stimulated by different wavelengths of light,and the combination of signals generated by them allows us to perceive different colours.
$(b)$ The inner ear,specifically the vestibular apparatus (consisting of the semi-circular canals and the otolith organ),is responsible for maintaining body balance.
$(c)$ The pupil is a small aperture surrounded by the iris that regulates the amount of light entering the eye. The iris muscles contract or relax to change the size of the pupil,thereby controlling the amount of light reaching the retina.