I don’t think that’s how it’s being used in that quote. “I made her tan so I could see cute brown girls” doesn’t make sense if it’s being used an an honorific because, like you said, it has nothing to do with skin color. It’s like saying “I used -Sama so I could see cute brown girls.”
The full quote is: “I only made Nagatoro tan was so I could see cute brown women cosplay as her”. The important bit is the phrase “Nagatoro tan” traditionally this would be romanized as “Nagatoro-tan” so it appears ambiguous.
Now it could be argued that since there is no punctuation that you’re read is correct, but seeing as the quote is from a Japanese author I personally see it being a misquoted honorific as much more likely.
I don’t think that’s how it’s being used in that quote. “I made her tan so I could see cute brown girls” doesn’t make sense if it’s being used an an honorific because, like you said, it has nothing to do with skin color. It’s like saying “I used -Sama so I could see cute brown girls.”
The full quote is: “I only made Nagatoro tan was so I could see cute brown women cosplay as her”. The important bit is the phrase “Nagatoro tan” traditionally this would be romanized as “Nagatoro-tan” so it appears ambiguous.
Now it could be argued that since there is no punctuation that you’re read is correct, but seeing as the quote is from a Japanese author I personally see it being a misquoted honorific as much more likely.
It’s a fake quote, so you’re reading a little too much into it.
Wikipedia says she has dark-coloured skin due to a tan, and she goes by Hayacchi, so it’s probably the colour they are referring to.