At the end of The Legend of Zelda: Twilight Princess, I always noticed something that struck me as peculiar:
Colin has Link’s sword and shield.
Now alone this is already pretty interesting of him, but I feel like it’s even more interesting when you parallel that with one of Colin’s quotes about half-way through the story. After pushing his friend out of harm’s way and getting trampled, he gets kidnapped, and once he’s rescued he says to Link something along the lines of “I understand now, that being strong doesn’t mean lifting stuff, it means being brave and doing stuff because you know you have to! I hope that one day I can be really strong, just like you are!”
It’s my opinion that at this point Colin already was “strong” as he wanted to be, and that he only gets stronger as the story goes on. In the manual for the game there’s a small blurb about Link that says the people of Ordon Village believe Link should become the village leader when he’s older and when he’s ready to take on the responsibility. At the end of the game, Link is already gone, so they would need another.
After the events of Twilight Princess, while Link is gone (presumably to become a knight or something to that extent), Colin would probably take his place as a ranch-hand and would slowly gain the same status and respect as Link, going far as even one day becoming Ordon Village’s Mayor.