Black magic :

Some kind of curse that causes damage to critters in a 1x1 tile around the afflicted. Has a visible effect. I like the idea of critters not wanting to be next to a target you cursed as if they've got some kind of disease.
The opposite of counterspell, making it harder for positive effects to affect the target. 

I also wish for dispel to ease out curses (across 15-30 mins) that have begun to set in or have reached their maximum effect, like the opposite of how curses ease in their negative effects gradually. If it's dispelled fast enough it's still just gone immediately. There's many critters that aren't afraid of being cursed at all, since they're friends with a white mage and can just get the curse dispelled for free, making black magic more of an annoyance/inconvenience compared to the scary potential of orange magic. If an orange mage threatens to smite you, you better figure out how to avoid that fate. But if a black mage threatens to curse you? Whatever, just get it dispelled for free!. This won't solve all of the problems, but at least makes curses scary if one is further away from home, or finding a white mage will take longer.

Since there has been confusion about this idea, let me illustrate with some examples.
Cursed 5 minutes ago => dispel => No curse.
Cursed 15 minutes ago => dispel => curse lingers for 10 minutes.
Cursed 30 minutes ago => dispel => curse lingers for 20 minutes.
Cursed 1 hours ago => dispel => curse lingers for 30 minutes (capped).
Silence would still be dispelled instantly as it's only fair with it being effective immediately.
Just like curses increase in effect since they've started afflicting someone, up to a cap. The linger will make the curse decrease in effect the closer it gets to being fully cured.

Also, to clarify. I DO NOT mind dispel being able to get rid of curses. I think it's great, because it sucks to be cursed for a long time. But equally, it sucks for black magic to not be effective when it can be cured easily. If anything, I'd be fine with weaker white crystals being able to dispel stronger cursed, as to not end up in a scenario where someone is cursed for two weeks.

Still hoping for more gray spells. I basically only ever cast extend. The other spells either cause too much strain, or have too little effect to be worth regularly casting. Or, they are good to cast, but very situational. (swift strike, timewalk, focus.)

I'd love a gray spell letting other mages charge their respective colors at gray sigils for X amount of attempts based on the charge used to cast it. This lets focus be immediately useful in combat still, whilst giving gray mages a worthwhile way to offer support using their power to affect the mind economy outside of combat.

For the benefit of any who may not be in the discord and prefer the forums!

There was discussion about black magic, and Ethos commented:  Black magic is in a bad place and we intend to expand it to contain more utility. It does what it's supposed to do well but it's boring to have most of the time. White magic is in a fairly similar place but it at least has Counterspell and had several spells reworked to make them more interesting.

As far as suggestions:

I do enjoy the idea about the 1x1 tile thing. It feels very flavorful. 

I also remember someone suggested a possible drain spell (whether it drains health, mind, or stamina could be interesting).

Possibly some kind of *slightly* more benign type of black magic might be helpful for more good/lawful mages to find some benefits. Simply a new curse with a shorter duration? Maybe induce temporary heavy sleeper on someone lol.  Maybe an illusion or something that could used to assist with pranksters trying to mess with someone without seriously harming them. Disguise one item as another? (Though lore-wise black magic is the most taboo for a reason so I could see how that might not fit.)

I feel like having places where only certain color mages can get into for different resources, and/or those who hold color charged crystals at various levels might help a better spread of the various colors to happen. Or maybe the mages have to be with the critters and there's a limited time for those who want in to pass through the 'door'.