You do dye your eyebrows when you're wearing a coloured wig, right?You wouldn't half-ass your cos and ignore something that's so easily done, right?
No. People typically have different color shades for their eyebrows and making your eyebrows unnatural colors makes your face look weird/old.
>>10961494But having differently coloured eyebrows and hair doesn't look weird? And how would it make you look old?
I recently did a cosplay with a blue wig and had to do this for the first time. Same with my sideburns, which couldn't be concealed by the wig. A little bit of a pain, but the final product ended up looking good.
I use a dyed wax for my eyebrows and beard. It's impressive how much of a difference it makes. Without dying your eyebrows you look like a dude with a random wig. If you use the right colour suddenly everything clicks and your brain stops seeing it as a wig and treats it like real hair.