The ingame actions 'target' and 'examine' are not associated with the message type "Action" but with "System" instead. Because of that you can't change their colour seperately.
Chat Tab changes were introduced with patch 1.62.
Example:
You target [XXX].
You examine XXX. She is a member of the YYY class in your realm.
Chat Tab changes were introduced with patch 1.62.
Example:
You target [XXX].
You examine XXX. She is a member of the YYY class in your realm.