You seemed to be saying that it’s assur to not wear braids,
To quote the mods:
You make a lot of assumptions of other posters thoughts and motives. It might be best to allow them to speak on their own behalves.
What I actually said:
Obviously you should ask your LOR, but before worrying about the nuances of which color nail polish (where you agree there is no Issur), you should certainly be Choshesh for a significant Shittas Rishonim and Achronim, who hold there is and Issur for non-braided hair.
P.S. The Mishna Berurah does bring the Magen Avraham down. Siman 75, Sif Katan 12.
On the internet question, you redirected with a story. I’ll try again: Who created an “internet” Issur, vs. a sensible geder for the possible nichshal of using it?
Finally, if Tznius is a sensitivity, then it is necessarily not a Halacha. You are sensitive to black nail polish, “Tznius (the poster)” is not. Others are sensitive to showing their faces in public.