The colour of a product plays an important role in consumer experiences, and in the context of pharmaceutical products, this could potentially affect a patient's expectations, behaviours, and adherence. Several studies have been conducted on adults, but little is known about children's opinions on colours of medicines and to what extent medicines' colour affects their acceptability. To address this gap, a systematic search in PubMed, Scopus, MEDLINE, and Web of Science was conducted. Two authors independently screened the titles, abstracts, and references of all articles and selected studies conducted on children (0-18 years old), assessing children's preferences or opinions about colour of oral dosage forms as either a primary or secondary objective or as an anecdotal record. A total of 989 publications were identified and, after screening, 18 publications were included in the review. Red and pink were the most liked colours and there appeared to be a relationship between the colour of a medicine and expected taste/flavour. The review also highlighted a scarcity of information, usually collected as an anecdotal record. Several gaps in the current knowledge were underlined, emphasizing the need of patient-centred studies to understand if the use of certain colours can improve or worsen the acceptability of a paediatric medicine. This will help inform pharmaceutical manufacturers and regulators on the role and need of colours in children's medicines beyond quality purposes.
Keywords: children; colour; oral medicines; preferences.