Ship69, are you using a ring binder, bound book, or something else for your paper system? I feel bad not getting back to your other discussion on priority (not posting a picture) but haven't had a chance to check back until now.
I use a bound book paper system. Yes, color is a great way to help manage lists. And I'm a fan of Frixion pens too
Regarding shifting priority and how you sometimes have the same tasks in 2 lists (a context list and again in an "urgent" list) --- I'll try to describe how I avoid the 2-lists problem.
I am a veterinarian and owner of a small animal clinic so in a typical day, in addition to the usual appointments, emergencies, and phone calls that go along with being a veterinarian, I sometimes have to take care of urgent issues with the bank, contractor, vendors etc.... I try to do the administrative tasks on our "closed" days so I can focus on patient care during clinic hours, but some days I juggle hats like I'm in a circus act.
So in addition to lists, I use color paper clips (specifically, Plastiklips) to denote urgency as well as to bookmark my lists.
Say, during a clinic day, I HAVE to call a vendor on the East Coast (US). I'm in California so will have to call the vendor by 2 pm (before our lunch break is over).
* I place a red Plastiklip on the side edge of the page with my context Calls. The red Plastiklip is my code for Urgent-must do today. Plus i place the clip on the top half of the page when it has to be done before 2pm.
So by glancing at my journal, I can tell that I have an urgent task to do by 2 pm. When I flip to that Calls page, I can tell which call I need to make either from the line mark I mentioned in the previous post or a dot in the center of the checkbox (both are ways I use to prioritize when I need more structure).
With respect to shifting priority, if the order arrives that morning and I no longer need to call the vendor, I would just cross out the task and remove the Plastiklip. Or if I still want to call but does not have to be today, I just remove the red Plastiklip.
Hope that made sense. Basically, I just write the task once on the list. I prioritize only if needed. I want to make sure I work on something that day, be it an urgent task or something from a neglected project, I place a color Plastiklip on the side edge (eg red for must do today, orange if family related)
Using the book edges have allowed me to maximize the book's physical 3D features. I use the Plastiklips on the the bottom edge of the page to bookmark the different lists for easy access eg green for errands, yellow for someday/maybe, pink for waiting for. Then the top edge is to bookmark current project notes eg remodeling, involved cases, etc...
Not sure how you have your paper system set up. Hope this gives you some ideas.
I couldn't figure out how to insert/attach images to the post so uploaded to my old Flickr account instead.
Here's the link to some images:
https://flic.kr/s/aHskVTfzmD
Hope that works.