Update Statement to replace text with regex

I want to run an update query on a document, where I want to find a specific text and replace it with another.
for ex:
“text”:“quick brown fox”

I want to replace brown with black, is there any n1ql query to do this change, now the find word can be anywhere in the document under any key.


UPDATE mybucke AS b
SET b = decode_json(REPLACE(encode_json(b),"brown","black"));

It changes in document fields too.