The picture was drawn by a police artist after a sighting of a young man acting suspiciously in a Greenock stairwell the night the teenager died, more than 27 years ago.
A trial has seen two versions, one black and white and another in colour - showing distinctive ginger or auburn hair.
At the High Court in Edinburgh, William Campbell, 51, agreed that in 1986 his hair was auburn but had since turned grey because of nerves.
Looking at the sketch he told the jury: "My hair may have been the same colour but it was a completely different style."
He also said the blue V-neck pullover the suspect was wearing would not have been his choice of clothes. Mr Campbell preferred T-shirts or sweat shirts.
On trial is John Docherty, 49, who denies murder and claims the true killer may be one of 41 people listed by his defence team.
Mr Campbell, whose name is on the list, was asked today if he killed 16-year-old Elaine and replied: "No".
Mr Campbell described how he attended a special school in Greenock, hampered by learning difficulties, and had also been diagnosed as epileptic which further blurred his memory of the time when Elaine's naked body was found near her Greenock home.
A police report from 1986 described the relationship between him and Elaine as "on talking terms at pool hall".
Mr Campbell told the trial that Elaine was his friend and would joke about him being her boyfriend to cheer him up when he felt low.
Another witness who, like Elaine and her friends, hung around a pool hall in Greenock said it was "ridiculous" his name was on the same list of suspects.
Port operator Martin Docherty, 45, said he would sometimes walk Elaine home but they were "just friends". Balding Mr Docherty also said that when Elaine was murdered he had blond streaks in his dark brown hair.
He said soon afterwards he stopped going to the pool hall because of a growing interest in motorbikes.
John Docherty, now of Dunoon, denies murder and claims that at the time he is alleged to have strangled Elaine in June 1986, he was with his parents, who are no longer alive, at their home in Greenock's Anne Street.
He also denies attacking another woman, Linda Hargie, on various occasions between 1990 and 1995 . The trial continues.