I'm with nanashi, I wouldn't mind it a bit darker, even just a light grey would be better. Background is kind of lame/doesn't work well too in my opinion.
Not that it actually needs to be changed though.
Can you reupload this? https://www.anime-sharing.com/threads/230213-たくし動画本舗-あな-あに-妹編-rj01012286.1291771/
All the links are dead.
and theres a shota version too if you have it: https://www.dlsite.com/bl/work/=/product_id/RJ01012293.html
Thank you.