two-tone: the hairstyle or the chance?

inspiration since ever: Violet le Beaux.

inspiration one: Guardian pharmacy having "Buy 1 Free 1" sale promotion for Beauteen hair dyes. (at first, i just wanted to grab a couple to re-colour my shoulder-length hair.)

inspiration two: nikki minaj's hair in the music video entitled "knock-out" with lil wayne. (it got me thinking about using brighter colours.)

inspiration three: then i wanted to create something like the wigs from MintyMix~ (two-tone FTW!)

right now, i am contemplating these questions:

1. vertical or horizontal two-tone? definitely vertical. horizontal is everyone's pick currently (trending).
2. lighter colour on the left/right or top/bottom? i'll figure out something after i choose the colours.
3. which combinations: black/blonde, brown/blonde, pink/blonde, brown/light brown? think think think.

do you have a good suggestion for me?