What denotes that the landing altitude was set automatically?

The landing altitude displaying in magenta color indicates that it has been set automatically by the aircraft's systems. In aviation avionics, color coding is often used to provide immediate visual feedback to pilots concerning the status of various parameters. Magenta typically signifies an automated setting that is currently active, differentiating it from settings that may be manually adjusted or require confirmation from the pilot.

In contrast, flashing indicators might suggest a warning or a need for attention rather than automatic setting. Green color typically indicates that a setting is active and confirmed but is generally used for manual inputs. A requirement for manual confirmation signifies that the altitude has not been set automatically, which is contrary to the condition for an automatically set altitude. Therefore, magenta serves as a clear and immediate indication of automated adjustments made by the aircraft's systems.