[quote=Dead Cruiser]
Everyone has a bit of every color, but one's current behavior and philosophy are generally what dictate their colors. See: Planeswalkers that have been different colors.Blue = Artifacts fo sho though. A spell that summoned craploads of swords would be hella Blue. Reminder that colored artifacts were introduced as the gimmick of the Primary-Blue shard of Alara.
[/quote]

But that's merely trying to ascribe a colour by the effect, rather than a colour by the 'why'. Beyond that, you're assuming that UBW works as 'summon loads of artefacts' or even [i]as[/i] an artefact, then saying that it's Blue--when the actual effect could be something more like grindclock, where you just tap it and check counters to see what the hell it does.

[hider=UBW Background Stuff]On top of that, Unlimited Blade Works itself exists because of Avalon, which is utterly White, and even then only because Archer/Emiya Shirou basically defines himself around saving people. Simply [i]using[/i] it, as the Reality Marble or as normal projection, damages a human body--oh, hi, Black. Even though Archer plans, he hasn't removed the tendency to throw himself in harm's way and just take the more direct option; plus all the fucking blacksmith connotations and smog. As for Green? Contract with the world to reduce the pressure on the destruction of UBW--and he's a Counter Guardian, so inherently part of the natural order.

Inside Unlimited Blade Works, it isn't the same as being inside a Blue artefact-spamming Land or something. A Reality Marble is the projection of a character's soul, essentially, onto the external environment: the effect might say one thing but the actual reasoning would be [i]completely[/i] different. Colourless incomprehensibility it is. [i]Not[/i] a mere blue because artefacts. 

If I had to turn it into a Magic card--and note that this is [i]not[/i] the same as how it will appear in the roleplay, if used--it would either be Black/White or Blue/White. It would not be mono-colour Blue. [/hider]