Although Callon experimented with various mediums such as oil and pastel, watercolor became his favorite. He developed a distinct and expressive style, treating the watercolor medium with a broad and unrestrained approach. The influence of the Impressionists is evident in his work, but Callon drew inspiration from a diverse range of artists, including Singer Sargent, Russell Flint, Wyeth, David Cox, and Peter de Wint.

His subject matter was diverse, encompassing portraiture, still life (with a particular emphasis on flowers), the industrial landscapes surrounding St Helens, and seascapes. However, it was as a landscape painter that Callon truly excelled, following the English tradition of painting outdoors in all weather conditions and seasons. Whether under the sun, in the rain, or amidst the snow, he sought to capture the essence of the ever-changing natural world.

Callon’s preferred painting locations included the enchanting Lake District, picturesque Anglesey, captivating Cornwall, and the rugged Yorkshire Dales. Among his cherished spots, the West Pennine Moors, particularly around Rivington and Winter Hill, held a special allure. Callon frequently returned to this area, captivated by its untamed beauty, striving to immortalize its essence on canvas.

Following his retirement, Callon dedicated himself fully to painting, devoting his time and energy to his artistic pursuits. His work graced exhibitions in prominent cities such as Manchester, Salford, Preston, and Liverpool, garnering recognition and admiration. In 2008, he held his first solo exhibition at the Atkinson Gallery in Southport, aptly titled “One Man’s Dream.” Subsequently, major retrospectives celebrated his artistic legacy, including those held at The Godfrey Pilkington Gallery in St Helens (2008) and Spring Cottage Gallery (2009).

Today, Colin Callon is fondly remembered as a tremendously talented and highly respected artist. His dedication to capturing the beauty of the natural world, despite his industrial upbringing, serves as a testament to the transformative power of art and the indomitable human spirit.