put lipstick on a pig

US /pʊt ˈlɪp.stɪk ɑːn ə pɪɡ/
UK /pʊt ˈlɪp.stɪk ɑːn ə pɪɡ/
"put lipstick on a pig" picture
1.

豚に口紅を塗る, 見かけだけを飾る

to make superficial changes to something that is fundamentally flawed or unattractive, without improving its core nature

:
Trying to fix that old car with a new paint job is like putting lipstick on a pig; it still won't run.
あの古い車を新しい塗装で直そうとするのは、豚に口紅を塗るようなものだ。それでも動かないだろう。
The new management tried to improve morale with a fancy new office, but it was just putting lipstick on a pig because the core issues remained.
新しい経営陣は豪華な新しいオフィスで士気を高めようとしたが、それは単に豚に口紅を塗るようなもので、根本的な問題は解決されなかった。