Primary colors are sets of colors that can be combined to make a useful range of colors. For human applications, three primary colors are usually used, since human color vision is trichromatic.

For additive combination of colors, as in overlapping projected lights or in CRT displays, the primary colors normally used are red, green, and blue. For subtractive combination of colors, as in mixing of pigments or dyes, such as in printing, the primaries normally used are cyan, magenta, and yellow, though the set of red, yellow, blue is popular among artists. See RGB color model, CMYK color model, and RYB color model for more on these popular sets of primary colors.

Any choice of primary colors is essentially arbitrary; for example, an early color photographic process, autochrome, typically used orange, green, and violet primaries. However, unless negative amounts of a color are allowed the gamut will be restricted by the choice of primaries.

The combination of any two primary colors creates a secondary color.

John Joseph Travolta (born February 18, 1954) is an American actor, dancer, and singer. Travolta first became known in the 1970s, after appearing on the television series Welcome Back, Kotter and starring in the box office successes Saturday Night Fever and Grease. Travolta's acting career declined in the early 1980s and continued to deteriorate for the rest of the decade. His career enjoyed a resurgence in the 1990s with his role in Pulp Fiction, and he has since continued starring in Hollywood films, including Face/Off, Ladder 49, and Wild Hogs. Travolta was nominated for the Academy Award for Best Actor for Saturday Night Fever and Pulp Fiction. He won the Golden Globe Award for Best Actor - Motion Picture Musical or Comedy for his performance in Get Shorty.

Travolta, the youngest of six children, was born and raised in Englewood, New Jersey, an inner-ring suburb of New York City. His father, Salvatore Travolta (November 1912 – May 1995), was a semi-professional American football player turned tire salesman and partner in a tire company. His mother, Helen Cecilia (née Burke, January 1912 – December 1978), was an actress and singer who had appeared in The Sunshine Sisters, a radio vocal group, and acted and directed before becoming a high school drama and English teacher. His siblings, Joey, Ellen, Ann, Margaret, and Sam Travolta, have all acted. His father was a second-generation Italian American and his mother was Irish American; he grew up in an Irish-American neighborhood and has said that his household was predominantly Irish in culture. He was raised Roman Catholic, but converted to Scientology in 1975.

Paul Guilfoyle (born April 28, 1949) is an American television and film actor. He is currently a regular cast member of the forensic television drama CSI: Crime Scene Investigation where he plays Captain Jim Brass.

Guilfoyle was born in Canton, Massachusetts. He attended Boston College High School and spoke at the 2005 commencement of the school's seniors. Guilfoyle enrolled at Lehigh University in 1968. He eventually graduated from Yale in 1977 with a major in economics. He studied at the Actor's Studio before building up a substantial theatrical reputation on and off Broadway, including 12 years with the Theatre Company of Boston, appearances in David Rabe's The Basic Training of Pavlo Hummel with Al Pacino and in David Mamet's Glengarry Glen Ross. He is often mistakenly referred to as the son of character actor Paul Guilfoyle but they are not related.

Guilfoyle appeared in Howard the Duck, and in an early episode of Crime Story, playing a criminal who takes a hostage, getting into a shootout with the Major Crimes Unit. He has since become one of the industry's leading character actors, specializing in roles on both the good and bad side of law enforcement.

Larry Martin Hagman (born September 21, 1931) is an American film and television actor, producer and director most widely known for playing J.R. Ewing in the 1980s primetime television soap opera Dallas and Major Anthony "Tony" Nelson in the 1960s sitcom I Dream of Jeannie. He is also the son of actress Mary Martin.

Hagman was born in Fort Worth, Texas. His mother, Mary Martin, later became a Broadway actress and his father, Benjamin Jack Hagman, was a district attorney. His parents divorced in 1936 when he was five years old. He lived with his grandmother in Texas and California. His famous mother became a contract player with Paramount in 1938 and occasionally took him to her movies.

In 1940 his mother met and married Richard Halliday and gave birth to a daughter, Heller, the following year.^{[citation needed]} Hagman attended the strict Black-Foxe Military Institute (now closed). When his mother moved to New York City to continue her Broadway career, Hagman again lived with his grandmother in California.^{[citation needed]} A couple of years later, his grandmother died and Hagman joined his mother in New York. At age 14 (in 1945) while attending boarding school, he began drinking heavily which led to serious health problems later in life.^{[citation needed]}