Justice Secretary Kenny MacAskill met the five low level offenders in Kilmarnock as they painted over graffiti underneath the viaduct on Portland Street.
The group, which is part of East Ayrshire Council's Community Payback scheme, worked to cover bright pink and green spray painted slogans.
And the wall will soon be covered in murals designed by pupils at Hillhead and Loanhead Primary Schools.
Primary five and six pupils entered a competition by drawing the town's famous buildings, including the Dick Institute and Dean Castle.
The winners' art will be painted onto the wall by a professional artist.
Fiona Nicolson, town centre manager at the council, is part of the Creative Minds project which is getting schoolchildren involved in the regeneration of the town.
She identified the graffitied wall under new laws which mean local communities can have a say in the type of manual labour offenders carry out.
She said: "It is good because it is getting rid of all the graffiti and creating an outside art gallery as well as involving the kids in the regeneration of the town centre.
"It is giving the children a stake in their town and an interest in it."
The painting team was given Community Payback hours instead of custodial sentences by the courts.
As well as covering graffiti the offenders will help elderly and disabled residents whose houses and gardens are in need of attention.
Marion Dick, community service assistant for Community Payback, said: "We have had lots of good feedback from the community that many of the jobs that have been done for elderly and disabled people have turned their lives around."
John Darnbrough, Community Payback team supervisor, said: "The projects we do are excellent for the community.
"We get people from the community coming up and saying what a great job we are doing."
Mr MacAskill, said: "We want low-level offenders out paying back communities by doing some tough manual labour.
"Punishment should be tough and we should be using these offenders as a resource to make improvements to local communities as pay back for the damage they have done.
"This is a great initiative in Kilmarnock which the community will see the benefit from."