I understand what it refers to, and I understand how lighting works.
Ann referenced the way that he term has come to have a double meaning, because it accurately refers to the racial dynamics of Broadway to the present moment*. You pointed out that this meaning wouldn't have been on the minds of people in 1880, and I was agreeing by pointing to the fact that it wouldn't have occurred to that society to even question the fact that Broadway only featured plays written and performed by white people.
*That present moment isn't just about casting. The recent AAPAC diversity report featured a number of striking statistics, including that of 153 design contracts during the 2018 - 2019 season, only 13 went to BIPOC designers.