Your pattern already extracts the first part into logger-name, which is good to know.
The surrounding characters are basically from Bash Coloring, which you would need to remove, first.
You can either include it in your grok pattern like I posted before, or you could use a mutate to remove them, like in this sample: https://gist.github.com/pauloconnor/4707710
I'm not sure whether the Escape-Character would need to be included, but this StackOverflow question has some input, possibly: https://stackoverflow.com/questions/33440366/grok-pattern-to-parse-the-esc-key