This isn't exactly what you were asking for (I think IJ has answered the actual questions, as asked) but here's some supplemental information and ideas.
Millie's (excellent and beloved) ColorText contraption isn't needed to color text in fields anymore. As of version 1.58 we're able to do it through the menus. (We're on version 1.63 now, so if you downloaded it recently this should be true in your copy) The drop shadow version of the contraption you linked to is still the best way to get a drop shadow effect though!
You can change the default color of a whole field by selecting it and using [ Widgets > Pattern... ], then select the color you want. You can change the color of a specific span of text by selecting it within the field and using [ Text > Pattern... ] to change the color for only that selection. You can also change fonts and create links using the Text menu.
I think the exact things you were asking for are tricky in Decker because of the nature of unlocked fields. But the concept of revealing distorted text or uncovering hidden text is absolutely possible by other methods.
For example, this is an alternate approach to the concept of 'user interactivity to reveal text'... but have you looked at the Interior Contraption?
If the 'true' version of the text is on another card it could be revealed by your player dragging something over it. This might give it a similar tactile experience to highlighting text -- but you also might need to explain what it is they're dragging around.
Or if you think of some other concept we might be able to help you build something to make it real.
Please do continue asking questions as they come up! It's always welcome and I'm very interested to see how your project develops.