I know that costuming has gotta be used as shorthand for the audience and some things have gotta be recognised but I feel like if you’re going to feature humanoids which are not human and humans from the far future - it’s a lost opportunity not to can draw on an absolute myriad of styles to signal how these people are Different.
go back twenty years and you see definite and serious differences in fashion and hair (the hair! specifically - you can always tell what year the portrayal of the 61 century hails from by the hair).
there are So Many ridiculous things to draw from just HUMAN history. I’m thinking of Angstrom and the other guy - so yeah the whole joke is that they’re NOT human when they look it - but surely it would make sense that they don’t look exactly like a 2018 man and woman style-wise?
wouldn’t it make sense to do something to them that makes them look just so slightly off?
you don’t even need to think outside of the box alien, you can just go back in time and grab a perfectly normal out of place human ‘long hair, slicked back as though wet/wigs/everybody is covered in tattoos/green hair that glows a bit/everybody is wrapped up hella tight/everybody’s wearing flared jeans’ from idk when and use it to signal alien