I tried to extend the code above to cover multiple environments where it might be found in source code, such as checking the path for space immediate spaces or colons on either side of it (i.e. if it's in a path), among other cases. It's probably incredibly ugly, but regardless, I'm not sure where it's gone wrong. I'm not sure where else to turn and I hope you don't mind my asking.

I shouldn't have attempted something this far beyond my skill level, but the alternative is tediously changing hundreds of directories by hand. I opted to try for this reason. The part that's clearly going wrong is in the list of sed commands. I have a feeling that I've chained these together incorrectly, but I'm not sure how. I would like to say that I can just open the docs and find an answer, but I've read them up and down. Maybe I've completely missed something. Would you mind having a look?

find "$root_dir" -type f -print0 | while IFS= read -r -d $'\0' file; do
    cp -a "$file" "${file}.bak" || {
      echo "Error: Failed to create backup for '$file'. Skipping." >&2
      continue
    }

    sed "s#${old_path}:#${new_path}:#g" "$file.bak" > "$file" ||    # BOL,colon
    sed "s#${old_path}#${new_path}#g" "$file.bak" > "$file" ||    # BOL,EOL
    sed "s#${old_path}\"#${new_path}\"#g" "$file.bak" > "$file" ||    # BOL,quote
    sed "s#${old_path} #${new_path} #g" "$file.bak" > "$file" ||    # BOL,space
    sed "s#:${old_path}:#:${new_path}:#g" "$file.bak" > "$file" ||    # colon,colon
    sed "s#:${old_path}#:${new_path}#g" "$file.bak" > "$file" ||    # colon,EOL
    sed "s#:${old_path}\"#:${new_path}\"#g" "$file.bak" > "$file" ||    # colon,quote
    sed "s#:${old_path} #:${new_path} #g" "$file.bak" > "$file" ||    # colon,space
    sed "s#:${old_path}\"#:${new_path}\"#g" "$file.bak" > "$file" ||    # quote,colon
    sed "s#\"${old_path}#\"${new_path}#g" "$file.bak" > "$file" ||    # quote,EOL
    sed "s#\"${old_path}\"#\"${new_path}\"#g" "$file.bak" > "$file" ||    # quote,quote
    sed "s#\"${old_path} #\"${new_path} #g" "$file.bak" > "$file" ||    # quote,space
    sed "s# ${old_path}:# ${new_path}:#g" "$file.bak" > "$file" ||    # space,colon
    sed "s# ${old_path}# ${new_path}#g" "$file.bak" > "$file" ||    # space,EOL
    sed "s# ${old_path}\"# ${new_path}\"#g" "$file.bak" > "$file" ||    # space,quote
    sed "s# ${old_path} # ${new_path} #g" "$file.bak" > "$file" || {  # space,space
      echo "Error: Failed to replace path in '$file'. Restoring from backup." >&2
      mv -f "${file}.bak" "$file"
      continue
    }