Enum Flag 

pub enum Flag {
    Invalid = -1,
    None = 0,
    Green = 1,
    Blue = 2,
    Yellow = 3,
    Red = 4,
}

Flags shown in F1 2019.

Flags are an essential tool to communicate the status of a race to the drivers on track. A green flag signals the race start or restart, while a yellow flag warns of hazards on track. The red flag aborts a race or session. The blue flag signals that a faster car is approaching from behind.

Variants

Invalid = -1

None = 0

Green = 1

Blue = 2

Yellow = 3

Red = 4