Reply To: script to copy strings of a certain color

There is a free script written by Peter Kahrel that may do what you want.
Here is a link. https://www.kahrel.plus.com/indesign/grep_query_manager.html

Here is a description for one of the features the script has. I copied the description off of his site.

Collect found items
Rather than executing the selected queries, you can instead collect whatever the query or queries match and print the found results in a new file. Your document is not changed at all. To collect the found items, check Collect found items. The found items are listed in a new document, sorted, and any duplicates and formatting are removed. To leave formatting intact, check Include format.