The 68-year-old "Dead Man Walking" star said she supports son Miles Robbins, 23, reported the Huffington Post.
"My son Miles is a musician and a DJ, and sometimes when his band performs they all wear dresses, and he has long hair," Sarandon said.
"I think the more crayons you have in your box to colour outside the lines, the more exciting it is."
The "Thelma and Louise" star, who has been a longtime supporter of The Trevor Project, a lesbian, gay, bisexual and transgender (LGBT) youth advocacy organisation, is slated to play the lesbian grandmother of a transgender teen in the upcoming film, "Three Generations".