Topic sentence________________________________. One very real problem is that of traffic signs and signals. Those that are red green colour blind have trouble seeing stop signs found on shady streets because they may not notice them against the leaves. In addition, they have trouble identifying signal lights and must memorize the position of light to know which signal is being given. Those who are fashion-conscious avoid brightly coloured wardrobe so that they will not wear clashing colours. Perhaps the greatest handicap of colour-blind persons is evident when they select occupations. For example, they cannot work as interior decorators, commercial photographers, airline or ship pilots, or railroad engineers. As most colour-blind people cope with their problems,, their handicap goes unnoticed.