I don't get what's so bad about "colored" function. That color is just about the return type of the function.

How do you return an error from a function that does not return a Result? You must call unwrap (panic) or change the colour of your function by changing the return type to Result and fix all the caller.

Similarly, if you want to use a future from a non-async function, you either call `block_on(...)`, or you change the return type to a future by marking the function async.

I don't think it is that bad. That's just the way explicitly typed programming languages work.