Okay.CounterAttack said:snip
Three is the maximum number of colours I'll allow, and that's pushing it. I won't take many people with three colours at their disposal.
And the thing about taking spells that originate from the planeswalker's 'home plane' is that by their nature planeswalkers visit many places and get used to many different ways of life. Take, for example, a character who grew up in the guild-dominant city-plane of Ravnica, but then visited Esper, a shard of Alara, before the Conflux. They would be able to draw on a fair amount of their spells from their home plane, but also a few from Esper, such as Tidehollow Strix or Etherium Sculptor. And then once they start getting into other places like Mirrodin or Zendikar, that provides even more choice to pick from.
I will, however, take into account the idea of planeswalkers choosing spells similar to their 'type'. Like, as you said, a vedalken could use a vedalken-themed list - probably blue or blue/white - but it really depends on where they're from. A Mirran vedalken would have a fair few artifact spells available.
But on the matter of types, I don't really want to restrict the characters too much, so I will allow a bit of leeway but nothing too extreme. I mean, you won't see an angel planeswalker using too many black-red hybrids like Avatar of Discord or Dread Slag. Also, no zombies. Largely because I hate them, but also because the planeswalker's spark only occurs in sentient races, and I doubt that zombies are sentient. Or independent, take your pick.
Not really much more to add there, other than I like where this is going, and that I want to have some spare time, so I can be able to join.