Some languages have names for more colours than others. In my English classes at school, I learned that the word “red” means both orange and red and blue means both dark blue and light blue, however, in Russian, there are two words, “синий” for dark blue, and “голубой” for light blue.
Scientists say that how languages deal with the names of colors doesn’t correlate with people's ability to distinguish colours. Most likely, language have words only for these colours that matter, that are practically important.
At the university, I learned that the old Russian language had a few different names for the colour that we call grey today. In the old times, people not only named colours but also marked the texture. Grey when referred to hair differed from grey when referred to a fur or to a wood. Later, grey became a general word for a colour, and now another word is needed to describe a texture. The only exception are colour names for animals' coat and for hair. So a person with red hair is “ryzhiy” (рыжий), but, say, an umbrella is orange (oranzheviy, оранжевый).
In Russian, there are seven basic colours: in the rainbow
red — красный [krahsnyi]
orange — оранжевый [arahnzhevyi]
yellow — жёлтый [zhohltyi]
green — зелёный [zelyonyi]
light blue — голубой [galuboi]
blue — синий [siniy]
violet — фиолетовый [fialehtovyi]
In English, there are seven colours in the rainbow too, however, they are slightly different. As you may see, the Russian rainbow has no indigo color.
Sometimes, a colour is more than just a colour. For example, since 1917, red has been a symbol of communism.
Like in English, “yellow” press in Russian means a type of journalism that presents little or no legitimate well-researched news. I have heard an expression, “this news paper is so yellow that it is more like orange”, that meant that the news paper was well-known for treating news in an unprofessional and unethical fashion. Orange follows yellow in the spectrum, so when the press becomes extremely yellow, it moves toward the next colour.
Light blue, when referred to a man, means gay. By the funny coincidence, police' licence plates in Russia are of light blue, that was the reason for endless jokes.
The word “green”, besides its newest meaning “environmental-friendly”, has some negative connotations. Thus, melancholy щк depression is of a green colour in Russian (тоска зелёная). There is also an expression “to get green with envy” (позеленеть от зависти).