The Greek that is translated as “adorn (yourselves) outwardly” or similar in English is translated in Nugunu (Gunu): as “pretty like a market plum.”
Keith Patman (in Wycliffe Bible Translators 2016, p. 79) explains:
“I had not expected to see the word for ‘plum’ right in the middle of 1 Peter 3:3, but there it was!
“When our team translated the verse from the Gunu language back into English, it read, ‘Wives, don’t try to be pretty like a market plum, by braiding your hair and putting on gold jewelry and beautiful clothes.’ Concerned for clear, natural, and accurate Bible translation, I asked the Gunu translation team, ‘Why did you use that word?’
“Their explanation made perfect sense. A favorite fruit in their area of Cameroon is the safou, or African plum. Sold in the local market, these plums look beautiful early in the day — all purple and shiny — and they taste great! But after a long day of sitting out in the warm African sun, although they still look pretty, the plums ave lost their freshness and they taste terrible!
“So ‘pretty like a market plum,’ for the Gunu people, a metaphor for superficial beauty, and that’s exactly what Peter was talking about in 1 Peter 3:3.”