The Australia international is on trial charged with causing racially aggravated harassment to policeman Stephen Lovell during an incident in south-west London in the early hours of January 30, 2023.
It is alleged that Kerr, 31, and her partner, West Ham midfielder Kristie Mewis, had been out drinking when they were driven to Twickenham Police Station by a taxi driver who complained that they had refused to pay clean-up costs after one of them was sick, and that one of them smashed the vehicle's rear window.
At the police station, Kerr is alleged to have become "abusive and insulting" towards Lovell, calling him "f****** stupid and white".
In his closing speech, prosecutor Bill Emlyn-Jones KC asked the jury: "What if PC Lovell had been a black male and what if she had called him f***** stupid and black?
"Now of course that is not a fair question, because black and white is not a fair swap.
"Calling a white man is not as loaded, so you can't just turn it around, it is not as easy as that.
"In the heat of the moment this was an insult delivered in reference to race and that is what the law prohibits.
"The test for you is the same regardless of the ethnicity in question. She was insulting him and, at the time, she was hostile to him by reference to his race.
"So the fact you will be able to think of much worse examples of racial aggravation is irrelevant.
"Would we consider this a racially aggravated insult if she had said stupid and black? Of course you would, it wouldn't even be contestable."
During the trial, the court heard character references from Chelsea teammates and former head coach Emma Hayes.
Carly Telford, a goalkeeper who played for Chelsea from 2017 to 2022, described Kerr as a "close friend" and an "introverted extrovert".
She said: "On the pitch you see the skills, the back flips (but) away from pitch, she's quite quiet and shy. Quite reserved."
She described her as "generous" with her money and said she often considered how she could cover costs for the younger players on nights out "to make sure they can celebrate with us".
Grace Forbes, defending Kerr, read out statements from Hayes, Chelsea captain Millie Bright and midfielder Erin Cuthbert.
Hayes, who is the former Chelsea manager and current head coach of the US football team, said Kerr was an "exemplary role model" and described her as "one of the warmest, friendliest, kindest and most considerate players".
She added: "She is calm and level-headed and mindful. She comes from a wonderful family. She has the biggest heart, she is a big kid at heart, I think she does well to manage everything that is thrown at her and the expectation that is placed on her."
Bright described Kerr as a "truly special human", while Cuthbert said she was a "great friend and teammate" who "has a unique knack of seeing the best in everyone".
The trial continues.
