Think recessive phenotypes as paper and dominant phenotypes as teared paper. Once paper is teared, it can't be fixed. Not even tape. It'll just leave that mess exposed. Same with dominant phenotypes. It just takes one dominant trait to change the looks of future offspring.
If you don't tear the paper, everything is fine. Same with recessive phenotypes. As long as there's no contact with any dominant phenotypes, the looks of future offspring will change.