Here are some expressions and words which have the names of colors in them. The meaning of each expression is given on the right.
Red-handed – to catch someone red-handed is to catch them while they are doing something wrong.
Black list – A black list is the list of people whom you cannot trust.
Blue-blooded – If you are a blue-blooded person, you belong to a royal or noble family.
Green grocer – A green grocer is a vendor who sells fruits and vegetables.
Green room – The color green is said to have calming effects on the mind. So, a green room is a room in the studio or theater where performers can rest.
Green fingers – to have green fingers is to have a natural ability in growing plants
Yellow pages – A telephone directory that lists the numbers of businesses and service providers
White elephant – This expression is used to refer to something that is very expensive but quite useless.
Red carpet – To roll out the red carpet is to welcome honored visitors with great respect.
Purple prose – an expression used to refer to prose that is too elaborate
Bluestocking – a woman who has too much interest in intellectual or literary pursuits. This expression often has a derogatory meaning
Yellow-belly – someone who has a yellow-belly is a coward