This one is probably going to be impossible.
I know of no affordable way to control the color temp and color of a light using a wall switch/wire unless you go DIY with LED strips meaning you are looking at smart bulbs. Once you are using smart bulbs all the rest of your requirements for the fail safe lights go out the window.
I use Zwave outlets and wall switches and I have a couple of Shelly 1s wired behind a regular “dumb” switch. I shun smart bulbs because I want all of my lights to operate like your fail safe lights. But this means I have to give up on color and color temp control.
There are more concerns than just the failure case, though as you are aware, I harp on that a ton as well. There is a strong case for usability as well. We’ve all been trained our entire lives how to turn on a light from a wall switch. They are easy to understand, intuitive, and require no special instructions or training.
But to get back to the failure cases, any technology integrated with OH is going to depend upon networking to work to control it from OH for from it’s native phone app. It could be the most reliable thing in the world but if your network goes down your gonna need some physical way to control the lights or you are out of luck. If the technology you choose comes with touch screens or the like, then you end out outside of the “shouldn’t be pricey” requirement.