Custom color and prefix support for logging

[agilgur5]

Having each service/task/background process have a custom color and prefix would be nice.

prefixes

Generally I'm fine with the default prefix of using the task name, but I think it's more commonly [task] rather than task: (the latter is what Kit currently does). Brackets are more obvious to me that it's a prefix as well, since they are not used in logs commonly (whereas colons sometimes are).

colors

Having each task log as a different color from each other is super useful for readability, IMO. A different color with good contrast by default would be great. (WCAG compliant colors are ideal, although this is a terminal, not a web interface, so WCAG does not quite apply, but the contrast semantics are still useful for accessibility).

task comparison for reference

Task lets you choose an "output mode" (group/interleaved/prefixed) and lets you customize the prefix per task. Colors can be globally configured and toggled with env vars, but doesn't seem like they can be customized per task.