Altering the messenger’s coloration shouldn’t be attainable. Messengers are functions that enable customers to speak with one another, they usually sometimes have a default coloration scheme that can’t be modified.
The colour scheme of a messenger is normally chosen by the builders of the app, and it’s typically designed to match the general branding of the app. For instance, the Messenger app from Fb has a blue coloration scheme, which matches the colour of the Fb brand.
