If the story is about the painting, the main character would be the blue - boy himself. He is the central figure in the painting and presumably the focus of any story related to it.
Since I don't know the exact 'blue boy story', it's hard to say. But surely the 'blue boy' would be one of the main characters. There might be others like his friends, family members, or people he meets during his adventures if it's that kind of story.
I'm not entirely sure as the specific 'top boy blue story' details might vary. But in the general 'Top Boy' series, characters like Dushane and Sully are often central figures.
The main character is likely the boy in the blue suit who is the subject of the painting. And of course, the artist Thomas Gainsborough who created this masterpiece.
The main character is Boy Blue, of course. He is the one around whom the whole story revolves as he is the shepherd in charge of the sheep.
The main characters are Pinky and the blue boy.
Well, clearly the main characters are the blue boy and Pinkie.
Since I don't know the exact 'baby boy blue story', it's hard to say who the main characters are. But surely the baby boy named Blue would be one of the main characters. There might also be his parents, siblings or other family members as important characters.
The main character is Little Boy Blue. And also the sheep he was supposed to take care of can be considered as important elements in the story, though they are more like passive characters.
The main character is Little Boy Blue.
Given that it's called the 'little blue boy story', the main character is presumably a young boy. The 'blue' part could suggest that he has some sort of connection to the color. Maybe he has blue eyes or a blue outfit that is significant to the story. Without more information about the story, this is all we can really assume.