Also, maybe consider hosting on Netlify or Vercel or Github Pages, or anything that doesn't require a server to spin up for a static site.
It also helps piggyback on the App Store for discovery.
Furthermore, maybe I am missing something, but where are the color management settings?
I'd be really interested in seeing someone do that in 20 minutes. If you ever decide to do that, please post here.
Obviously it was a bit of a facetious comment, and props to the author for building a full iOS app. This is definitely not that.
*I have a bunch of color related function code snippets I use for dataviz, so I did not write the utils file "from scratch" just now. Also chakra-ui is a great component library that helps with quick prototyping.