Q. Hello Rabbi I am waiting for a response about my shailoh of lo yilbosh for a man dyeing his hair nowadays.

A. Shulchan Aruch (Y.D. 182: 2) rules that a man who colors even one white hair black, transgresses the Biblical prohibition of “Lo Yilbash,” (Devarim 22: 5), a man should not dress like a woman. Whether a person whose hair prematurely turned white is permitted to color his hair dark so that he will look his age rather than older than his age, depends on the purpose and reason of the dyeing. If done for beauty reasons many Poskim prohibit, but they permit when it is done to avoid embarrassment or to be hired, secure a job or maintain office. (See Sheorim Metzuyonim Bechalocho 171: 1, Igrois Moshe Y.D. 1: 82 and 2: 61, Nishmas Avrohom Y.D. 2: p. 137, quoting R. Z.S. Auerbach zt’l )
See also question 563, on whether a man can trim his eyebrows if they are unruly and get into his eyes.
We wrote: “Shulchan Aruch (Y.D. 182: 1) rules on the prohibition to remove bodily hair growth. However Mordechai (Shabbos 50: 327) permits in cases of great discomfort or pain.
Nishmas Avrohom (Y.D. 182 p. 140) quoting Horav S.Z. Auerbach Zt”l that permits the removal of embarrassing excessive hair between the eyebrows.
Horav Shlomo Miller’s Shlit”a opinion is that the eyebrows can be trimmed for the sake of one being able to see properly, but not with the exactness and meticulousness typical in women’s facial treatment.”
Although some contemporary authorities may be lenient, the Rov’s position would be similar to above in our case. He added that the fact that there are dyeing products manufactured and marketed specifically for men and many men do use them, is of no relevance when they are used just as a beautifying agent.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a