Each of the colleges works quite differently. You can't really just group them up.
Gold Wizards: Gold wizards tend to be wealthy as fuck and they tend to recruit from older students who are already experienced in a trade such as metallurgy or alchemy. Gelt for example was an adult before he joined the college in search of greater alchemical knowledge. It's very prestigious to be a gold wizard and they own a lot of stuff including for example most of the Empire's alchemy guilds.
Jade Wizards: Jade wizards tend to be family members, typically the sons and daughters of other Jade wizards. They travel around and get rid of blights and cause easy births and great agricultural yields wherever they go.
Amber Wizards: Amber wizards do whatever the fuck they want to. They live out in the wild and nobles often try to lure them into their territory so they'll keep out infestations of greenskins and beastmen.
Grey Wizards: Grey wizards recruit from an early age to indoctrinate them in the way of the Jedi to teach them the noble ways of the Grey Wizards. They hold immense power (as in empress assassinating power) and thus are typically watched closely by their elders.
My thoughts on it are basically that its linked to how the College's powers and psychology relate to society:
-Gold College basically adds direct economic value. As such they are encouraged to live fabulously extravagant lifestyles, because a Gold Wizard's best way to make money is to sell their expertise, either in crafting fine goods, improving the economy or proliferating technology. To compound this, the Gold mindset is highly logical, as long as its more effective to earn money legally they would.
-Grey College creates nothing, but it DOES have a lot of ways to TAKE away economic value and political power. Even a Grey Journeyman would be hard to keep from robbing people blind with no resistance or oversight save for other Grey wizards. Thus they are hugely constrained and strongly indoctrinated. The Wind's mentality of suspicion, ambiguity and perspective also means that they interact oddly with rules interpretations from normal peoples' perspective. The ability for the same activity to be considered legal or illegal depending on complex context is a feature, not a bug. It encourages the Grey Wizard to explain themselves a lot.
-Jade and Amber Colleges are druids and tribal shamans respectively, and don't really need much supervision beyond the basics, leaning on a preexisting culture instead, though it helps that they like remote areas with fewer people around. The Jade do produce wealth while the Amber don't however.
-Light and Celestial Colleges are spiritual/academics, who by nature of the Wind they wield, effectively recuse themselves from society. Don't need to control them much, they'd be happy nerding it out over theology or mathematics and not bother people much.
-Bright College are basically dedicated battlemages and their College runs along Do Or Die lines, hammer in discipline and if they can avoid killing themselves they have a long and illustrious career burning the enemies of humanity to death.
-Death College PROBABLY has a bit of a problem with slippage to necromancy, though they, like the Bright College, are a bit on the destructive side(and depressive to boot). Tighter controls probably just to make sure they aren't going to the dark side.
Best option there is he taints it and dumps into the Citadel WAGH! field and all the greenskins spontaneously turn into Dwarf Fortress cats. So every time a dwarf approaches the Citadel they get adopted by half a dozen cats that reproduce by spores and bard tales get more silly.
...I could see him do this.
Stepping in here to note that if any Dwarfs had even the inkling of a suspicion that humans were trying to learn Rune magic, there would be a Dwarf Waaagh.
Uh...humans DO learn rune magic. The Dwarfs won't teach it, and you can't steal a Rune by studying an item with it. The concealment and copyright is in the process, and humans can't really spend a few decades spying on an apprentice to learn enough without being caught or getting bored
instead of trying to steal it because lol sounds fun
We're not taking it. We're giving it to Ranald.
GM confirmed that Ranald will take it and do unspecified things with it.
Trying to imagine how Mathilde will deal with all that Waaagh energy by giving it to Ranald.
Mathilde: " 'O Ranald the Night Proweler, who watches over those who steal in the night; I need to fence some burning hot divine energy, you in?"
The hottest goods in the world!