The actor stated he was trolled for his weight from when he first appeared on the soap at just 11 years old.
However, Colson spoke proudly about the changes he made for a healthier lifestyle.
The Coronation Street star explained it was first linked to his storyline of Craig.
He told presenters: “I proposed I’d be up for losing weight if it would fit with a story.
“I sat down in the back end of 2019 and said I’m going to make sure I can do this and make it easy for myself, I feel like it’s something I could do.”
While Colson originally set to lose weight as part of a storyline, his plans were changed when the coronavirus lockdown was introduced.
“I started and then in March the world changed with lockdown,” he continued.
“It could have been the perfect excuse to knock it on the head… But for me it was the perfect opportunity to stop and refocus on what was important to me and what mattered to me.
“I learned a lot about myself and I enjoyed it.
“I realised it was more important for Colson than it was ever going to be for Craig.”
When talking about his transformation, the 22-year-old stated he would set small goals to stay on track.
He added: “I just sat down and made little goals and those goals constantly changed. It’s just been an experience that I’ve really enjoyed.
“I realised how much self respect I had for myself verus how much I have for myself now.”
While he said he stays away from the scales, some reports have estimated he may have lost as much as 10 stone.
Colson has regularly shared weight loss updates on social media and gave details of his workout routines.
He has slimmed down by pounding the pavements and has often shared pictures of himself post-run.
The TV star has also built his strength with rowing and training with heavy weights and kettlebells.