Two observations about Rich Text custom metadata fields:
1 - In Dark Mode, the default color when making an entry to such a field is not visible - it only becomes visible when highlighting it and/or changing the font color
2 - If such a field is chosen in the List View, changes in font color, italics, bold, etc. are not depicted in the list view. Is it possible to add this feature?
The next maintenance release will fix this.
This is currently intentional - due to the limited space in List view only a plain text representation (ignoring attributes like font, style, images etc. and without line feeds) is shown.
Why not leave it up to the user? If only straight text with no fonts or line feeds or images is desired, various plain text fields are available for that purpose. If the rich text fields permitted display of that information, all sorts of uses for DT3 could arise. Sure it could become difficult to read in certain situations - let the user figure that out and only put in data that is useful. Perhaps images could automatically be reduced to thumbnails given the extreme chaos that could cause in the output - but beyond that i think that would be a terrific feature for users to explore with an understanding of the “risks”.
beyond that i think that would be a terrific feature for users to explore with an understanding of the “risks”.
Would you like me to send you the support tickets on those who ignored the risks or thought the risks were inconsequential? Hahahaha! 
(Couldn’t resist.)
I understand that is said mostly in jest.
But if you are worried about users causing havoc by not realizing risks - then consider all the problems that can and do happen from scripting!
But you support scripting enthusiastically - and it is one of DT3’s best features because of the flexibility it gives people to use the software for their own needs. The same would be true for viewing rich text custom metadata in the list view.
I understand that is said mostly in jest.
Indeed.
then consider all the problems that can and do happen from scripting!
We do, of course. However, many people don’t want to do their own scripting or even create their own smart rules. That does limit the danger considerably.
If the rich text fields permitted display of that information, all sorts of uses for DT3 could arise.
PS: We could chase all kinds of options with “the possibility someone may find a use for it”. However, time and resources have a limit and @cgrunenberg’s list of things he could do is longer than our collective lifetimes. Fixes are primary with other requests being considered by other criteria, including the popularity of such requests or sometimes the ease of implementation. Trust me, I’ve had many “great ideas” that are really only one-offs or wouldn’t serve the majority. You all haven’t seen many things I’ve done or suggested behind the scenes.
PPS: Don’t forget that DEVONthink is not the only application we have to tend to in here. Again, time and resources aren’t in endless supply.