1- red and green. they can occasionally look good together, but they usually don't
2- butcher vanity (technically made with synthv and not vocaloid but that isn't the point)

red white ﹠ blue /j uhmm probably brown ﹠ green 😭 theyd have to be a certain shade to actually look good

my fav vocaloid song uhmm thats a rly hard question (𓏼 ˊ͈ ᵔ ˋ͈𓏼 ) ill just list some faves

god-ish 、 hyperdontia 、 plus danshi 、 bocca della verita 、 any KIRA song 、 the vampire 、 86 、 pneumonoultramicroscopicsilicovolcanoconiosis 、 nakakapagpabagabag 、 + more

yellow and dark blue...ugh

1. purple and yellow idk I don't like either of them in general
2. black rock shooter by supercell maybe... idk I'm not that into vocaloid these days so I kindof forgor

Violetish and green

green and red, xmas is a nightmare bc of this

i. I don’t personally like yellow and blue together, but I know they can work together. But regardless.
ii. Probably Heart Pie Dancehall.

Rolling Girl, specifically cillia's cover.

Black + orange/red bro ew

Green and Red. I hate when ppl say they look good 2gether, they dont even if theyre compliemnting colors. same w/ purple and yellow and blue and orange .

uhhh aishiteitanoni OR adipocere

UH VOCALOID SONG UH UHH AS OF RN BUG

Dark green and greenish brown.

Walking by steampianist