Local residents came out to see the free light show, which was the result of the Shine competition organised by Borders Art Fair.
More than 100 young people responded to the call to reimagine the 19th-century century neoclassical building with their very own designs.
Some 30 of the best were projected onto the building to provide onlookers with a two-hour display.
The winner of the junior category was Oliver Wright, 11, from Broomlands Primary School, who said: “It has boosted my confidence and made me very proud.”
His mum Mandi Wright added: “Myself and his dad, Richard are so impressed by his artwork which is difficult to achieve digitally. To see Oliver being recognised within the competition has been an absolute delight and we are so excited for him and the projection on Kelso’s town hall.”
The senior category was won by Christopher Blackwell, 17, from Jedburgh, whose inspiration came from Russia.
He said: “When I found out I had won I could not believe it. Having my art projected and winning the art voucher has been an amazing experience for me and it has been an honour to do this competition.
“I got my inspiration from the St Basil's Cathedral in Moscow - it fitted in well for the general aesthetic of the building in Kelso’s town square. The building to me every time I saw it looked very formal building much like the cathedral but lacking in colour.
“When I was thinking of ideas for Kelso’s town square this cathedral instantly sprung into mind and it matched all the coloured pens I had and was also my kind of art style.
“My artwork took me a week to do with two days practising and planning and the rest drawing the actual art. First I did it with a pencil and then had to go over it again in pen and colouring it in.”
The winners each received a £100 Cass Art Voucher donated by Art Society Borders, who sponsored SHINE alongside local businesses Hastings Legal, Douglas Home & Co and Focal Point Furniture.
Frances Fergusson, Borders Art Fair director, said: “It was brilliant to see the designs come to life as massive projections, completely transforming the town hall.
“The idea behind the competition was to encourage young people to use their artistic skills in a way that would help bring the community together for a free event that would brighten up a dark winter evening. And that’s just what it did.
“Art and creativity are so important and we really want to nurture them in the next generation. This was a way we could do it and achieve some pretty spectacular results, which we hope will inspire the young people to carry on with their art.”
The public can see the designs projected onto the building again on February 19, from 6pm to 8pm. The Dessert Diva café and takeaway will be open for hot drinks and snacks.
The competition was funded by the Scottish Government.