In some circles it is not acceptable for the men to be into their clothing and styles. That is why the men (usually the more yeshivishe) will all wear the same clothing.
Because, assuming the poster is legitimate, her question is foolish.
If Group X demands that you wear black socks, then you can rightfully ask if the boy is truly committed to Group X if he, in fact, wears grey socks. But she didn’t ask if he was committed to that group. Instead, she questions his yiras Shamayim. That, IMHO, is foolish.
The very notion that wearing grey socks means that your yiras Shamayim is any more or less than downright foolish.
The Wolf