This story is impressive in several ways. It's different. The descriptions of marbles are quite splendid, and match the dreamlike imagery throughout the story. You are definitely inside the boy's mind, so I would like you to consider rewriting the story in the first person. The language you use has the sound of an individual, unusual and slightly colloquial, and the boy's view of his parents is unique. He observes them with the same love as his marbles, in colours and patterns!
There is some wording that might be considered technically wrong or awkward, but it created such an atmosphere that I would hate to see it changed. I think the first-person idea would fix that, as the language would then be completely the boy's.
The imagery of the coloured door at the end...red for rebirth and creation...is a perfect ending/beginning.
Very nicely constructed. Poetic. Let me know if you rewrite it.