In English I think we generally say "all that glitters is not gold". The origin goes way back, but Shakespeare used it in 'The Merchant of Venice'. As you said, it does refer to appearances, it means that something that looks good on the outside may, in fact, be worthless.
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New2grammarCan I use it on a beautiful girl?It's not a common phrase, but I suppose it could work.
A. Look at her. She's a looker, isn't she?
B: All that glitters is not gold