Definition
A standardized system of colored arcs and lines marked on the face of an airspeed indicator that visually identifies the aircraft's operating speed ranges and limits. The standard markings include a white arc (flap operating range), green arc (normal operating range), yellow arc (caution range, smooth air only), and a red radial line (never-exceed speed, VNE). A blue radial line is added on multi-engine aircraft to indicate best single-engine rate-of-climb speed (VYSE).
Plain English
Colored bands and lines painted on the airspeed dial that show, at a glance, which speeds are safe, which require caution, and which must never be exceeded.
Context Anchor
Seen on the airspeed indicator during the normal instrument scan, especially during takeoff, approach, landing, descent, and any time speed is changing.
Derivation
A code is a system of signs that carries a specific meaning. Here, the colors act as a simple code: each color band on the airspeed indicator tells the pilot something important about the airplane's speed range.
Why Pilots Care
They provide instant visual recognition of safe and unsafe speed ranges so the pilot can maintain proper airspeed without diverting attention to read exact numbers.
Analogy
They work like colored zones on a machine gauge: green is normal, yellow means be careful, and red marks a limit you must not cross.
Intuition Check
Do not treat the colors as decoration or rough suggestions. On an aircraft airspeed indicator, they mark approved operating ranges and limits for that specific airplane.
Example Sentence 1
During preflight, the instructor pointed to the airspeed color codes and reviewed what each arc meant before the student's first solo.
Example Sentence 2
When extending flaps, the pilot verified the airspeed was inside the white arc shown on the airspeed color codes.