If you delete or move text that was affected by colorizer and then undo, the colorizer will be where the cursor was before the undo instead of where it originally was before undoing.
Here are two reproducible examples:
Indent (>>) and then undo (u). You will see that the colorization is one indentation level further than it should be. (See #71.)
Cut (dd) and then undo (u). You will see that the colorization is one line lower than it should be.
An easy fix is to reload colorizer after every undo. I came up with this neat workaround:
coffebar
commented
1 year ago 
If you delete or move text that was affected by colorizer and then undo, the colorizer will be where the cursor was before the undo instead of where it originally was before undoing.
Here are two reproducible examples:
>>) and then undo (u). You will see that the colorization is one indentation level further than it should be. (See #71.)dd) and then undo (u). You will see that the colorization is one line lower than it should be.An easy fix is to reload colorizer after every undo. I came up with this neat workaround:
However, this is a workaround and not a solution.
Operating System: Gentoo GNU/Linux\ Neovim Version: 0.7.2\ Colorizer Version: 36c610a9717cc9ec426a07c8e6bf3b3abcb139d6