The reasonable person in trademark law
n50. There are other ways in which to compare, for example, two colors. See Lawrence B. Ebert, Trademark Protection in Color: Do It by the Numbers!, 84 Trademark Rep. 379, 404-05 (1994) (proposing use of scientific method of color comparison in trademark infringement cases).
[LBE's TMR article was cited by the Supreme Court in Qualitex.]