Medieval Christians insisted on Jews having different dress from them. In 16th century Poland, yellow hats were decreed for Jews – with an exemption during travel. Presumably, without the hats, many Jews dressed like Polaks. Things indeed changed under Russian government:
1804 Russian law: (soon after Poland was divided and Russia got a big part of it)
Jewish children attending parochial or district schools, may wear Jewish dress, but those attending gymnasiums must wear German or Polish [style] dress for the purpose of uniformity.
anyone who would like to be elected as a Member of Town Council from among the Jews in the Gubernias incorporated from Poland, for general order and uniformity, must wear Russian or Polish dress, if they do not like to wear German dress. In the Russian Gubernias where Jews are permitted to live, Jews elected to Town Council must wear German dress.
nobody can be elected or appointed to any position in Kahal or the Rabbinate without being literate in [ Russian, German or Polish]
Manufacturers, artisans, artist and merchants will be permitted to visit other Gubernias and even capitals due to business purposes for a specified period of time, but only by a Gubernator issued passports, about which [Governers] in their turn have to send monthly reports to the Minister of Interior [on passport issuing].
Jews (including their wives and children) temporarily traveling outside of the Pale, have to wear German [style] dress no different than that of others. If they wear traditional dress, they shall be sent back [to the Pale] by the Police.
More came in 1840s and 50s