Final answer:
Dr. Colton is most likely a clinical psychologist, which is the largest subfield of psychology focusing on diagnosing and treating psychological disorders.
Step-by-step explanation:
Dr. Colton identifies himself with the largest subfield of psychology, which is widely acknowledged to be clinical psychology. Therefore, Dr. Colton is most likely a clinical psychologist. Clinical psychology focuses on the diagnosis and treatment of psychological disorders and other problematic patterns of behavior. This subfield is essential to mental health care and often involves therapies and interventions to assist individuals with their mental health needs. Clinical psychology is a broad domain that encompasses various therapeutic modalities to address a range of psychological issues, making it one of the most public-facing and diverse areas of psychology.