Search database for font color?

Since my earliest use of DTP I have added my in-text notes to articles using the format of specifically colored text enclosed within triple square brackets. I just like this better than the little post-it-like notes. Now I would like to know if I can search a group of documents for ones with such notes. In other words, search by text color. I could search using “[[[” but text color would be more helpful.

I searched in this forum, and in Joe Kissell’s latest book, but do not find this addressed.

Non-alphanumerics are not indexed (save a few related to currency).
An example of what you’re referring to would be helpful.