Use less aggressive terminal colors

[natefaubion]

This is a bit of a taste thing, but currently almost everything is either colored green or red. I think spago is also just indiscriminately coloring everything on stderr as red, even subprocess output piped from spago run. It's a bit much IMO, and most of this (aside from green checkmarks) could be normal colors or even dimmed.

[f-f]

I have noticed this as well, and it's a bug. I think it really comes down to stderr being colored red (which started happening not so long ago?), so we should paint "normal" logs with the default terminal color.