When does a baby seagull change colour?

Baby seagulls, or gull chicks, typically change color as they mature from their downy, fluffy appearance to their adult plumage. This process usually begins around 5 to 6 weeks of age, with chicks gradually losing their brown and white down feathers and developing their juvenile feathers. The full transition to adult coloration can take several months to a few years, depending on the species.