The colors are important if you are going to do async. They tell you significant details about the functions you are using. The issues most people have with col

The colors are important if you are going to do async. They tell you significant details about the functions you are using. The issues most people have with colored functions aren't that they are have colors. It's that the colors don't compose. The languages that deal the best with this pick a single color and commit to it. Go and any BEAM language make every function async effectively and handle the coordination for you. They succeed because their runtimes will do a better job than you will 99% of the time. For the rest they give you some tools to reason about it. Rust however doesn't come with it's own runtime it's meant for the kind of development where you are building your own runtime or bringing one. For that reason the colors (i.e. types) are surfacing all of that complexity for you and helping you handle it. The bigger problem as I see it is that the rush for async has left a lot of crates choosing either sync or async only and so finding the crate that for your particular use case can be hit or miss. Half the db libraries may be sync only and half of the http libraries may be async only and then you have to figure out how to marry the two. If you can live in one or the other world only you are fine. It's when you have to live in both simultaneously that things get hairy.