The incident happened at about 23:00 on Wednesday.
The 21-year-old victim was walking along the road from the top of Baker Street when an unknown man shouted racially-aggravated abuse at him.
The suspect is white, in his late teens or early 20s, between 5ft 7in and 6ft tall, with red or blond short hair.
He is of a stocky build and was wearing a red or orange hoodie.
Officers are urging anyone who can assist them to come forward.
Insp Mike Bennett said: "For this young man to be subject to such unprovoked abuse as he went about his daily business is shocking.
"This behaviour is absolutely unacceptable in our community and I'd urge anyone who witnessed this incident, or has information which can help with our inquiries, to come forward."

He also resigned from the 2014 World Cup organising committee.
Mr Teixeira, who led the federation for 23 years, had come under pressure over corruption allegations, which he has denied.
He has been investigated on suspicion of crimes including tax evasion but has never been convicted of any offence.
Former Sao Paulo Governor Jose Maria Marin, 79, will be replacing Mr Teixeira in both posts.
Mr Marin read out the letter in which Mr Teixeira announced his "permanent resignation".
Mounting speculation
Mr Teixeira said he was leaving with a sense of "mission accomplished".
"Football in our country is associated with two things: talent and disorganisation," he wrote.
He said he had done what was within his reach, sacrificing his health.
Last week, Mr Teixeira announced he was taking leave of absence for medical reasons. However, he did not specify the nature of his health problems.
Mr Marin said nothing would immediately change at the football federation or at the World Cup organising committee under his command.
Pressure started growing on Mr Teixeira to resign after new corruption allegations surfaced earlier this month.
But state federations voted unanimously to confirm him in the posts.
In 2001, the Brazilian Congress investigated Mr Teixeira on suspicion of 13 crimes, including tax evasion, money laundering and misleading lawmakers, but no charges were brought.
He has also been investigated for allegedly taking kickbacks from a marketing firm that worked closely with Fifa in the 1990s.
And the English Football Association accused him of improper conduct during bidding for the 2018 World Cup.
He has denied all the allegations and has never been convicted.
Police are appealing for witnesses after a young man suffered "shocking" racial abuse while walking on Hawick's High Street.
[NEXT_CONCEPT]
The head of Brazil's football federation, Ricardo Teixeira, has stepped down from his post, days after taking sick leave.