Any advice on this process that doesn't sum up to "Do what you want."?
Most things come down to this in writing...
Anyway, I would look at the character's philosophy of life and how they approach things. Like, okay, a "sliver-walker" or a "walker-who-likes-slivers" might, in your mind, need access to all five colors of magic in order to summon each and every sliver the game has ever made. Fine. But what's that 'walker
like? What does that 'walker care about?
Why is that 'walker so obsessed with slivers? Is it because he loves the strong sense of community that the sliver's natural link provides? If so, maybe he is mono- (or primarily)
. Is the character a researcher who became exceedingly knowledgeable on slivers to the point where she could control them? Maybe she's
. Does the 'walker believe that slivers are an inherently apex race, or could be the most efficient path to power and domination?
.
With character creation, it's probably more important to look at personality and motivation than actual spellcraft. Take Lukas Harran, for instance. DavFlameRock made him a
character who, due to circumstances, can only use
mana. Now, admittedly, my writing of him may have him appearing a bit more
than Dav likely intended, but that's my fault, not his. The point is, the colors of mana used in a character's magic does not necessarily HAVE to match the colors that identify that character.