The solution for exercise 1 in chapter 6.2 - Grammar of Wider World 4 - Student's Book by Suzanne Gaynor, Kathryn Alevizos and Carolyn Barraclough
Question
If a person can’t see different colours, why is it difficult to do the things below?
Answer
Cook → It can be difficult to see if food is cooked properly or if it has gone bad.
Choose clothes → They may choose colour combinations which other people think are strange.
Drive a car → Colour-blind people ofter have problems distinguishing between red and green, the colours on traffic lights.
Read a Geography book → On maps, countries are shown in different colours, so it is easy to see where the borders are. These colours may look the same to someone who is colour-blind.