Unfortunately, the fix described in your post does NOT fix my problem.
It is not the keywords, comments, strings or any of the other named items that are displayed in light cyan, but the rest which is not covered by any of the Syntax Highlighting settings.
SELECT * FROM tablename WHERE col = 'something'
In the text above "tablenane" and "col" are displayed in light cyan, the rest has the color as selected in Syntax Highlighting settings.
If I remove the checkmark in front of "Keywords" the words "SELECT", "FROM" and "WHERE" become light cyan, too.
But nowhere can I change that default color to something else, or at least I did not find out how to do it, yet.