https://jira.qos.ch/browse/LOGBACK-1392 will improve the situation as if I well understand JANSI has kinds of heuristic too (see https://github.com/fusesource/jansi/blob/master/jansi/src/main/java/org/fusesource/jansi/AnsiConsole.java#L205)

But implementing logback own heuristic could allow to make it works without JANSI dependency.