In the bedrock version of Minecraft (meaning Pocket Edition and so on) the villagers retain their clothes prior to being infected by a zombie. However, with this add-on and in Java Edition (meaning the original PC version of the game) they get a new pair of blue pants and a turquoise t-shirt. Personally, I think it's more realistic that they keep their default clothes, but hopefully it's useful for someone out there.
- Download Resource .McPack
- Activate the pack for a world in-game