Halle, 48, claimed that there could be "psychological damage" to her daughter, who might wonder why her natural appearance "was not good enough".
The evidence she presented included time-lapse photographs showing how much Nahla's hair had changed. She said that Canadian model Gabriel had denied making any alterations, so she had a strand analysed at a laboratory to obtain proof.
Gabriel, 39, was in court for the hearing, but the actress did not attend, and was instead represented by a lawyer.
The former couple were in a relationship from 2005 until 2010 and became embroiled in a bitter custody dispute after their split.
Earlier this month, it was revealed that Halle is hoping to dramatically reduce the amount of child support she pays Gabriel by more than $12,000 a month – from $16,000 to $3,800.
Halle has been married to French actor Olivier Martinez since July 2013, and three months later, they welcomed their son Maceo-Robert.
Nahra pictured with father Gabriel Aubry in Las Vegas in 2013
In 2012, Gabriel and Olivier were both taken to hospital after getting into a brawl with each other at the actress' home on Thanksgiving.