I just posted on IG about my loli outfit for 83z fancon. The theme was red and white. That’s easy. I chose AP’s Heart Pockets Frill JSK.
The thing is, no matter what the theme is, I’ll always try to make whatever’s in my wardrobe work. (Doesn’t help that I have over 50 loli outfits. Yikes.) But the point is, it is my interpretation of the theme. When handsome oppa boss said dress theme for his concert is yellow and/or vintage, I knew some people would be wondering how to fit that. For a moment, I was wondering about my own loli wardrobe. Did I have anything yellow? And then, I realised I did!
I would have worn this:

AP’s Yumemiru Macaron JSK. It’s yellow and released in 2008. A rather old (vintage) print from a major loli brand. Yes, when people think of vintage, they have a certain style in mind, but vintage can simply mean something from the past. I could also have chosen an old school loli style with the maxi pad head dress, but I don’t think there are yellow outfits in that style. They are mostly either black or pink. There is also full white, saxe, and red.
When I was still working full-time in an organisation, one year, the organisation’s D&D’s theme was movie characters. I wore my Alice loli outfit to represent Alice. I also have other loli outfits with Disney character prints like Cinderella, The Little Mermaid, Belle from Beauty & the Beast. Of course, it would be fun dressing up as a character, but there was no hard and fast rule that said you had to come as a movie character.
So, you see…it’s just your interpretation of the theme.