Last night I built a series of tables to compare the color assignments of spells against the spell allocations of the classes. I then moved several spells to a color such that their origin class could still use them. I'm still working on this but I can't move *all* the spells over because that would lead to the classes being unbalanced. Their characters change. Note also that subclasses have slightly different spell lists from each other.
Bards: They lose the ability to raise dead and cure wounds as these are white major spells. They pick up a large number of nature and wilderness spells. In 1st edition D&D bards used the druid list, so this echo is nice to have. Their spell selections overlap with druids in Abora and wizards in Balcra, which lines up well with their history, and also forming one of the more eccentric lists in the game. College of Valor has minor Shunra, College of Lore has minor Valra, and the new College of Secrets has minor Sodra.
Clerics: Most cleric spells turned out Valran anyway, but they're going to need to rely on domains for what access they get to other colors. Sodra has the undeath spells but new to clerics will be the concentration interference spells (Addle) and mind blanking attacks out of Sodra. Still, the list feels like a cleric list. They overlap druids in Valra and Warlocks in Sodra.
Druids: Healing spells are divided between Abora and Valra. Abora gets most of the status removal effects, Valra gets the straight cures wounds spells and raise dead spells. As druids have access to both this means they, not clerics, are now the kings of healing. Their direct damage abilities take a dive, especially at 7th level where almost their entire spell selection was Shunran (red). They still have the ability to deal out damage, but its conditional and pales in comparison to the raw force wizards and warlocks can muster. There's some good ones though - Rusting Ray devastates constructs, Accelerated Decay can do a number on undead and under a clear sky Call lightning was reassigned to green so that at least this particular iconic attack spell would remain on their list. Green does "Damage via weather" where Red is more raw energy attack.
Warlocks are getting a scary boost in spells available count. By count they'll have twice as many spells at their disposal as before, from no less than the two most aggressive alignments in the world. Going into playtesting this one concerns me the most. On top of that, the patron type gives minor access to a third color - Fey green, Old one blue, A new yet to be devised patron for Valra and the existing fiend subclass will need a boost to offset having a smaller spell list than the other three.
Wizards in past D&D editions have had no rhyme or reason to their spells, which I've found annoying at times. Since all wizards cast from red and blue they now have an elemental feel to them. Blue also has mobility, illusion and divination effects well covered, red has the martial arcane spells like mage armor. The original wizard list also had a lot of Sodran magic, which is lost unless the player makes choices to recover it. In addition to a schools, a wizard can be a generalist, which has the powerful ability to add a third major domain and have minor access to both the remaining domains, meaning the ability to cast roughly 80% of the spells in the game. As a class, wizards can now cast anything, though individuals will always have types of spells they can't use.
Sorcerers likewise can cast anything, but they are far less codified. As a class they have no alignment of magic. Instead their own personal alignment influences they spells they can learn - they can always pick spells from that alignment freely. For the other alignments they must have twice as many minor spells known as major access spells, so gaining a major access spell from a color they've never learned before means picking up two other minor spells of that color. Since their spell selection is already tight this steers them mostly into 2, maybe 3 colors at most, but in a way they are the most flexible casters of all.
I really need feedback on these ideas. It's a massive amount of material to prepare and its very disheartening to read over the thread and seem to be talking to myself. Also, I know I'm making mistakes - I'd like some help in finding them.