Physiology The Helmholtz theory’ of colour vision states tha A There are three kinds of cones in the retina responding to the three primary colours B There are two kinds of cones called dominators and modulators. C There is only one kinds of cone and the colour is recognised only in area 17. D There are seven types of cones responding to the seven colours of the spectrum. 💡 Explanation The Helmholtz theory' of colour vision states tha ✓ Correct Answer: A. There are three kinds of cones in the retina responding to the three primary colours