Coloured hats are sometimes used to symbolise attitudes towards various abstract concepts.

In Tibetan Buddhism

Tibetan Buddhism

Tibetan Buddhism is the body of Buddhist religious doctrine and institutions characteristic of Tibet and certain regions of the Himalayas, including northern Nepal, Bhutan, and India . It is the state religion of Bhutan...

, several sects are distinguished by the colour of their hats:

• Yellow Hat - the Gelug
  Gelug
  The Gelug or Gelug-pa , also known as the Yellow Hat sect, is a school of Buddhism founded by Je Tsongkhapa , a philosopher and Tibetan religious leader...
  
   sect
• Red Hat - the Nyingma
  Nyingma
  The Nyingma tradition is the oldest of the four major schools of Tibetan Buddhism . "Nyingma" literally means "ancient," and is often referred to as Nga'gyur or the "old school" because it is founded on the first translations of Buddhist scriptures from Sanskrit into Tibetan, in the eighth century...
  
  , Sakya
  Sakya
  The Sakya school is one of four major schools of Tibetan Buddhism, the others being the Nyingma, Kagyu, and Gelug...
  
  , and Kagyu
  Kagyu
  The Kagyu, Kagyupa, or Kagyud school, also known as the "Oral Lineage" or Whispered Transmission school, is today regarded as one of six main schools of Himalayan or Tibetan Buddhism, the other five being the Nyingma, Sakya, Jonang, Bon and Gelug...
  
   sects
• Black Hat
  Black Crown
  The Black Crown is an important symbol of the Karmapa, the Lama that heads the Kagyu school of Tibetan Buddhism. The crown signifies his power to benefit all sentient beings. A corresponding crown, the Red Crown, is worn by the Shamarpa...
  
   - the Karma Kagyu
  Karma Kagyu
  Karma Kagyu , or Kamtsang Kagyu, is probably the largest and certainly the most widely practiced lineage within the Kagyu school, one of the four major schools of Tibetan Buddhism. The lineage has long-standing monasteries in Tibet, China, Russia, Mongolia, India, Nepal, and Bhutan, and current...
  
   sect

In computing

Computing

Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...

 slang

Slang

Slang is the use of informal words and expressions that are not considered standard in the speaker's language or dialect but are considered more acceptable when used socially. Slang is often to be found in areas of the lexicon that refer to things considered taboo...

, hackers and crackers

Hacker (computer security)

In computer security and everyday language, a hacker is someone who breaks into computers and computer networks. Hackers may be motivated by a multitude of reasons, including profit, protest, or because of the challenge...

 are identified according to their intentions.

• White hat
  White hat
  The term "white hat" in Internet slang refers to an ethical hacker, or a computer security expert, who specializes in penetration testing and in other testing methodologies to ensure the security of an organization's information systems...
  
   hacker, who hacks for beneficial purposes
• Black hat
  Black hat
  A black hat is the villain or bad guy, especially in a western movie in which such a character would stereotypically wear a black hat in contrast to the hero's white hat, especially in black and white movies....
  
   hacker, who hacks for malevolent purposes
• Grey hat
  Grey hat
  A grey hat, in the hacking community, refers to a skilled hacker whose activities fall somewhere between white and black hat hackers on a variety of spectra. It may relate to whether they sometimes arguably act illegally, though in good will, or to show how they disclose vulnerabilities...
  
   hacker, who hacks with ambiguous ethics

Also in computing is a business company called Red Hat

Red Hat

Red Hat, Inc. is an S&P 500 company in the free and open source software sector, and a major Linux distribution vendor. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina with satellite offices worldwide....

.

In the educational theories of Edward de Bono

Edward de Bono

Edward de Bono is a physician, author, inventor, and consultant. He originated the term lateral thinking, wrote a best selling book Six Thinking Hats and is a proponent of the deliberate teaching of thinking as a subject in schools.- Biography :Edward Charles Francis Publius de Bono was born to...

, six coloured hats represent six thinking states.

• White hat – Facts & Information
• Red hat – Feelings & Emotions
• Black hat – Critical Judgement
• Yellow hat – Positive
• Green hat – New Ideas
• Blue hat – The Big Picture

In Chinese culture, a green hat symbolises a cuckold

Cuckold

Cuckold is a historically derogatory term for a man who has an unfaithful wife. The word, which has been in recorded use since the 13th century, derives from the cuckoo bird, some varieties of which lay their eggs in other birds' nests...

. This issue is addressed in the movie, Green Hat

Green Hat

Green Hat is a Chinese film from 2004 and the debut of screenwriter Liu Fendou. Starring Li Congxi, Liao Fan, and Dong Lifan, the film tells the story of two men, one a bank robber, and one a police officer and their shared problem of unfaithful partners...

.