If Grand Architect is used to turn an artifact creature blue until end of turn, and you then copy that artifact creature, is its color a copyable attribute? For example, if I use Grand Architect to turn Blightsteel Colossus blue until end of turn, and I then copy Blightsteel, is the copy blue as well?
Not necessarily. An effect that changes an object's color (such as found in Grand Architect's second ability) is not an effect that carries over when another object becomes a copy of that object (C.R. 706.2). With limited exceptions not applicable here, copy effects are the only kind of effects that can be copied (C.R. 706.2).
Copyable Attributes (Changed Color)