I've been using k [1] to get pretty much the same functionalities but, being written in zsh, it's terribly slow.
Your program looks nice but I would love to have an output closer to k in term of colour [2], at the moment it feels way to noisy to me.
You can't grey out the columns in exa until I land configurable colours, which I hope to get done relatively soonish. But you can use the --colour-scale (or --color-scale) option to colour file sizes based on how big they are. The person who submitted the feature request (https://github.com/ogham/exa/issues/65) used k as a direct example.
[1] https://github.com/supercrabtree/k
[2] https://raw.githubusercontent.com/supercrabtree/k/gh-pages/f...