in Toad (I’m using 9.6.11) Go to View -> Toad Options. Click Editor -> Behavior. There is a button called Syntax Highlighting. On the Highlighting Tab (opens by default) is a list of styles, clicking on the style will show the options selected for that style…
For example in my setup (which is my install default), Reserved Words are blue, Comments green, Strings Red, etc.
Scroll through and you’ll see the options, and you can change as necessary for your needs.