Guess the colour.
Have you ever heard the phrase “Richard Of York Gave Battle In Vain”? It means “Red Orange Yellow Green Blue Indigo Violet”. It describes the order of colours in a rainbow. It is very easy to tell one colour from another in this case. But there are plenty of other words that deal with colours.
How many names of different colours do you really know in English? Try to make up a bouquet of tulips and check your knowledge.