Colin Paul Kerr was born on January 31, 1950 and was one of six children of the author Jean Kerr and the New York Times drama critic Walter Kerr.

At the time of Colin's death on April 30, 2024, he had two living brothers, Gil and Greg, and his only sister Kitty. Colin's oldest brother Chris died in 2010, and Colin's twin brother John died in 2016.

Colin and John were educated at Portsmouth Priory Prep School in Rhode Island. At Portsmouth, both of them played Football, Basketball and Track & Field. As a senior, John played point guard on the varsity basketball team, and at 6' 4", Colin was frequently the leading scorer. As the captain of the Varsity Track & Field team in his senior year, Colin also placed first in multiple events for his ability to throw the shotput and javelin. The twins also excelled in the classroom. In his sophomore, junior, and senior year, Colin was first in his class, and his brother John was second in his class in both his junior and senior year. Both of them went on to study at Harvard University. At Harvard, Colin majored in Classics and Classical Archaeology. After graduation, he served as a youth program director for a year in Cambridge, Massachusetts while he completed the pre-med courses required to apply to Medical School.

In 1977, Colin graduated from the University of Pennsylvania Medical School and completed an internship at Children's Hospital National Medical School. He interrupted his residency to obtain a master's degree in public health and a law degree from UC Berkeley.

In 1986, he completed a residency in Family Medicine at Case Western Reserve University. Colin taught and directed residencies at East Carolina University from 1986 to 1988; at Penn State. University from 1988 to 1992; at SUNY Stony Brook from 2001 to 2005; and at the Santa Rosa Family Practice affiliated with UC San Francisco from 2007 to 2009.Those positions were interspersed with stints of private practice in California (Winters Medical Center, Winters, CA, 1979-1983), Pennsylvania (Myerstown Family Practice, 1992-1994), and positions as staff physician and Medical Director for Federally Qualified Health Centers in California (Portola Health Care, Portola CA, 2010-2011) Peach Tree Health Care, Yuba City, CA 20122013), Nebraska (Webster County Community Hospital, Red Cloud, NE, 2016-2017, and Arizona (Community Health Centers of Yavapai, Prescott, AZ, 2017-2021). Colin also practiced with an HMO (Kaiser Permanente Medical Center of Santa Rosa, 2009-2010). He was a leader in the developing field of evidence-based medicine and the author of numerous publications including one article for the Hastings Law Journal in 1989 about the case of a sick child wrongfully denied health care coverage by California Medicaid.

In addition, Colin published The Family Practice Newsletter for his colleagues for 33 years. In August of 2021, Colin finally decided to retire. Having spent over 40 years helping patients, his only disappointment was that he hadn't spent more time with his children and extended family. After Colin's wife Donnis died in late January of 2022, Colin decided to move to Maine to be closer to his siblings, to enjoy the falling snow which he could see from his living room, and to enjoy his love of reading and uncovering the knowledge that new technology made accessible at the touch of a button.

In his words, "It is a great age to live, to have tried love, and to have pondered the infinite."