Apologies for using the Issues page for this.

It would be lovely to support hex colours, or MiniMessage formatting to allow more more customization.

Example below:

SleepInfo: "&#f656f6Sleep &7» &f%percent% out of a minimum of 25% sleeping."

No problem using the issues page for suggestions, really I prefer it over e.g. the Spigot discussion page.
Hex colors should be possible using this kind of format: "&x&2&9&1&f&f&f G" (in this case a G with code 291fff) So &x with the hex code afterwards split with a & between each character.
I do like the suggestion of adding MiniMessage, and will have a look at implementing it in the future.

Unfortunately this would be a bigger effort than I first thought, as running a mix of legacy color codes with minimessage ones isn't possible. Minimessage authors want it to be Minimessage only, so I think this would have to be a full move to minimessage including converting old messages to minimessage equivalents.