This Italian brand of drinking water comes in two colors: red for "very fizzy" and blue for "lightly fizzy". The testimonials also reflect it in their personality.
"I'm a Mac." "And I'm a PC".
Sanrio's Patty & Jimmy are well played in this trope: Patty is the red oni, because she excels in sports, but fails in studies. Jimmy is the blue oni, because he is not very athletic, but has A+ grades in such classes as math, and reading. In addition, the two friends wear their respective colors... most of the time.