I think the image is sweet, I like the subject you have chosen, and while it is not really original, it is heart warming!
I think it is a good idea to enhance the colours, they do look better here. I think however, something looks a little unnatural about the sharpness, did you change something there?
Maybe it is also because the focus isn't fully right, it seems to be on the trees rather than the elderly couple.
The composition is quite good, symmetrical and well working, but probably a different angle could have enhanced the image, one where one could see more of the path that lies ahead of them, or less both would have worked but like this it is a little boring, and also image - wise not so well.