I went away to the seaside with a couple of friends, and we were **lively** to say the least – most of my friends didn’t feel it necessary to bring any clothes which wouldn’t embarrass anyone who knew them, like crazy t-shirts, walking in the street with dressing gowns and hats that could put a circus to shame.
We wanted to know if we could daven in such clothes, and more specifically — is it better to wear a funny hat or no hat at all?
In the discussion, somebody brought in Crocs – of any colour – which could be classified as not suitable for tefillah. Yet most people i know where such shoes of Yom Kippur, the holiest day of the year.
Then we decided that there is no proof from there – if the halachah is to wear slippers, then it is not disrespectful, because that is what the Torah wants. On a day, however, when Yeshiva Bochurim like us walk around formally dressed with normally black polished shoes, it may be a bit of a ????? to wear Crocs.
(Somebody said that in the “Yeshiva-bochurim-on-holiday-matzav”, the dress code there WAS the norm, but I don’t know how reliable that was)