Here's why:
* Visibility: These colors are highly visible and easily distinguishable, making the dog stand out to others and helping them avoid accidental collisions.
* Safety: The bright colors warn drivers and pedestrians of the dog's presence, especially in low-light conditions.
* Identification: The color helps people identify the dog as a working animal and understand that it's assisting a visually impaired person.
While red and yellow are the most common, some guide dogs may wear other colors, depending on the organization or individual preferences.