Canon EOS 80D - Manual (Page 126)

AF Area Selection Modes
126
AF Using Color Tracking
By default, AF will be performed based on color tracking.
When the AF area selection mode is set to Zone AF, Large Zone AF, or
45-point automatic selection AF, focus is achieved as follows:
 In One-Shot AF Mode
Focusing on a still human subject in the AF area is made easier.
 In AI Servo AF Mode
Focusing on a human subject in the AF area is made easier. If no skin
tones can be detected, the nearest subject will be focused on. Once focus
is achieved, AF points are automatically selected so that the camera
continues to focus on the color of the area it focused on first.
* In [8C.FnII-12 Auto AF pt sel.:Color Tracking], you can set whether to perform
AF by tracking colors. If [1: Disable] is set, focus is achieved based only on AF
information (p.422).