Your only option without repainting is stripping and staining to bring out the wood grain. Is the wood oak, poplar, pine, birch?

I can't identify the wood, but it's something with almost no grain, very light-colored. Just plain. But this is a poor finishing job, so they look worse than they would have just plain. Stripping is not fun, but I imagine you're correct. Thanks for the answer.

Select Pine and Poplar have very little wood grain. It's most likely one of the two.

perhaps a new set of prefinished doors would be way less hassle?

Great Idea andre! I haven't made a decision on this, but it really is nice to be able to get ideas and advice here. Thanks.

It depends on your budget. A solid core wood door in oak or birch is expensive.

A hollow core door is what it is. A cheap replacement.