You just shouldn't worry. We don't know nearly as much about the universe as one would believe. Unless you want to become astronomer, it probably won't make any difference to your life either.
All you really know is that some guy looked through his goggles and noticed a red shift. Although numerous credible scientists have since then confirmed that it's there, you likely haven't even seen it yourself. For all you know, it might not be true at all. But assume it's true that there is a red shift.
One possible explanation is that the universe is expanding. Probably that's the reason, too -- but you don't know. Another explanation would be that the universe has been expanding a million years ago, which is what we see, but it isn't expanding any more (maybe it's shrinking right now!). We only know what we see (and not what is true), and light travels at a quite finite speed whereas the universe is huge. So anything we see has already passed from history to legend to myth a long, long, long time ago.
Another explanation would be that the "vacuum" is not a vacuum but a very light red mist, so you only see its tint at astronomic depths (or incidentially there is no such mist in the solar system). Or maybe there exists mass that you can't see (something like a black hole, but weak enough so light can still escape) which the light has already travelled past, and that mass is now acting in the opposite direction. Maybe there is ... whatever. Maybe it's the Devil playing tricks on your eyes to test your faith. We cannot know, we can only tell what's plausible.
If you want to procedurally create a galaxy, create something that "looks like a galaxy" to you. Plausible, good enough. Who cares about the truth.