Let's examine each pair: (a) Vitamin A - Night Blindness: This is correctly matched. Vitamin A deficiency is a common cause of night blindness (nyctalopia). (b) Vitamin B$_{3}$ - Pellagra: This is correctly matched. Pellagra is a disease caused by a deficiency of niacin (Vitamin B$_{3}$). (c) Vitamin D - Colour Blindness: This is not correctly matched. Vitamin D deficiency causes rickets in children and osteomalacia in adults, affecting bone health. Colour blindness is typically a genetic disorder, usually X-linked recessive, affecting the perception of colours. (d) Folic acid - Anaemia: This is correctly matched. Folic acid (Vitamin B9) deficiency can lead to megaloblastic anaemia.