EDIT: A full year after this post. I was still missing 0to255.com so much, I typed in the address in nostalgia and fain hope only to find the site back up and running. I am so happy! It’s still my favorite color tool, right along with coolors.co.
My favorite color tool for years and years, the one I’ve used most consistently of any of the tools I’ve used, has been offline now for three weeks and my best guess is that it’s gone for good. One day I used it, all was normal, no notices, nothing, and the next day, it was gone. It left me a little stunned.