I would say "No Preference" because you have some groups where the multi-color borders are all-but demanded, and then others where it simply doesn't work at all.
Example: Sentai Teams are ALL ABOUT THE COLORS and you'd be very remiss on not having those multi-color borders. However, if you were to present something like Lafiel Abriel and her command staff from Banner of the Stars... Yeah.
Example: Sentai Teams are ALL ABOUT THE COLORS and you'd be very remiss on not having those multi-color borders. However, if you were to present something like Lafiel Abriel and her command staff from Banner of the Stars... Yeah.