Jumping off of @transreliquat‘s excellent color-pie discussions, here are some of my own ideas for changes:
Make it clearer that Blue does not have a monopoly on being smart.
This might be too entrenched to properly change by now, but Blue should be about seeking knowledge, not about just being smart; Accord from Worm is a staggeringly smart character who’s mono-White, being completely concerned with grand plans to improve the world and establish order.
And Blue could stand to improve its cold-and-rational Vulcan image, too- I like condescending Counterspell flavor text, but I would love to see more Blue characters who are reckless, tyrannical, or wildly misguided in pursuing new knowledge.
Give Black a PR overhaul.
Black gets a bad rap. It’s got demons and vampires and discard and kill-spells, and it’s admittedly hard to get “ambition” shown in clever ways in a game about magical combat. (See also: the trouble with Red’s underrepresented passion.) But there are interesting, nonviolent ways of showing a willingness to succeed at all costs- it’s nice to see a pay-life-to-draw spell, Painful Truths, that’s shown as harsh pragmatism, not a demonic blood rite.
This could be helped in a way that also breaks up Blue’s monopoly on intelligence: make Scrying primary in Black. Blue already has plenty of card-draw and library manipulation, and it would be a great way for Black to express, “I refuse to accept what is fated for me.”
Give Green some more terrifying weirdness.
Nature is fucked up. So why is Green so often on the treadmill of Elves, Shamans, and Beasts? “Letting nature run its course” and “letting everything harmonize in their roles” lead to all sorts of weird evolutionary outcomes. Evolution isn’t an elegant march from worse to better, it’s a kludgy, surreal mess of modifications where the only criterion is “good enough.”
Bring on some great weird-creature artists, give Green some Future Sight-level weirdness at higher rarities, and evil Elves are always a plus.
Anyone have further points/counterarguments/things I missed?