I bought a normal alarm clock, vinyl records, a land line and read a lot of books. I sold all my electronics except my phone which I put in a safety deposit box at my bank. I did go to the library a few times a week to write emails and take care of business. The OCD I struggled with was with checking things. For example going back and fourth to see if the door is locked. The habit loop of checking our phones is one of my theory's and also using them as coping mechanism for anxiety as well. I've done other things like more exercise and certain supplements. I wouldn't say my OCD is completely gone but the experience has helped me better understand my relationship with these devices. I ended the 6 weeks because I lost my wallet and needed to reestablish my identity so I went and got my phone. My take on it since is that these devices are digital drugs. For example just looking at a display releases dopamine.
It sounds like you tried a lot of things and made some changes during that time.
Although this is getting way off topic of the original post in this thread, I'm not sure of the connection between just looking at a display and the release of dopamine. Without knowing much about the subject, I would think that it would be the interface presented by the device that triggers the release of dopamine, or in other words how the information and user interface elements are presented to engage the user. In other words, if the user interface is designed to reward the user for certain behaviors, then perhaps the link to dopamine release would be clearer. Most devices (and this includes not only digital devices but analog devices as well) are designed with an objective in mind, and if you carry out certain tasks and behaviors (such as by lifting the arm of the record player to place the needle on the spinning LP), you will get some kind of "reward" or result. Arguably, this is where the generation of dopamine comes into play, not necessarily just by looking at a display with or without the expectation of reward.
I'm also a little confused about the approach you took towards conquering what you believed was OCD. Perhaps you thought that not having any digital devices at all would remove you of the need to check things? As I understand, OCD could be just as likely to manifest itself in the need to check the location of keys, doors closed, whereabouts of people and so on—these things are not exclusive to the world of digital devices. I would agree that the operating systems and apps of digital devices like the iPhone are designed to engage and remind people more than ever (with notifications, alerts and so on), but there are also more ways to monitor your usage and curb the frequency at which you find yourself engaging with your devices. Have you tried using Screen Time, or created custom focus settings to block out the notifications you don't want? I've found that these things can help raise our awareness of how much we use our devices and what we use them for, without presenting an either-or choice to keep them or toss them entirely. At any rate, it sounds like you mostly wanted to just get rid of what you felt were "distractions," which is an admirable sentiment if you feel like your devices are doing and can do nothing to help you to better enjoy and be more productive in life.
I did find what you said about how people sometimes use devices as a "coping mechanism for anxiety" to ring true, especially in my case. I also believe that this is not exclusive to digital devices, though. People have invented all kinds of coping mechanisms over time to dull their pain and uncertainty. When it comes to psychological disorders like OCD, the disorder could well be the manifestation of some base-level anxieties that need to be dealt with first. Getting rid of devices might help in the short term, but arguably may not provide the solution to the underlying anxieties and issues (such as the need for companionship or friendship, problems with coworkers or family members, fears about the future and so on).
Anyway, this is something of a digression from the OP's original "fussiness" about the color consistency on the screen of the iPhone they purchased, but there might be some interesting ties in there between our desire to have things "just right" when it comes to our life or purchases, and the possibility that this could become a genuine neurosis.
