It's not about the skin being dark, but about burned.
Koreans view burned skin tone as not pretty because historically people who have are poor, since they probably work in the fields. Even and brighter skin tones means that you are rich and doesn't need to work.
It's totally different from where I live, for an example, since most people think that if you have sun burn than you have enough time to be on the pool or the beach and doesn't need to work too much.
I know that, in the webtoon, probably sounds like people with darker skin tones aren't pretty, but I think it wasn't really the intention... ╮(￣▽￣)╭
Basically, they aren't probably being racist, but I know that it can be understood like that. (▰˘◡˘▰)
Yeah it’s not racist, it’s colorism and it is still worng
Does having a slight dark skintone makes you ugly??? Authornim is something else.
Sure people can have preference but a normal appearance should not be deemed as "ugly"