I think that claims like "x is green at t" should receive a relational analysis, like: GreenlyOccupies(x, t). I also think this can be independently motivated: we need the relation of greenly occupying for other reasons and cannot reduce it to a monadic greenness, so the Ockhamly thing to do is to reduce greenness to greenly occupying.
But here is a hitch. If x is green at t and non-green at t*, then how has x changed? It seems that both at t and at t*, x greenly occupies t and fails to greenly occupy t*. Granted, we might say that x is green at t and non-green at t*. But on the view in question, being green or being non-green are not real properties. So there seems to be no real change. If there is a real property in view, it's being green at t and being non-green at t*. But it is always the case that x has both of these properties. For every time t**, x is green at t at t**, and x is non-green at t* at t**.
Should this bother me? Perhaps not. I have a reductive analysis of accidental change. Accidental change between two times is just standing in a relation to one time and not standing in that relation to another time.
But that doesn't seem right. For instance, let's say that I am interested in the year 1716 (why? because I'd like to figure out what was going on in Leibniz's mind in that year given his correspondence with Des Bosses and Masson). Then I stand in a relation of being deeply interested in to 1716, but I do not stand in the relation of being deeply interested in to 1715. So on the view just offered, I have accidentally changed between 1715 and 1716. But I didn't exist then, so I didn't change then.
Maybe I can rule out this case as follows. The relation of being deeply interested in is a Cambridge relation in respect of its second relatum--1716 is no different for my being interested in it. So perhaps accidental change between two times requires standing in a relation to one time and not to another, where the relation is non-Cambridge in respect of either relatum (it's easy to see that it also shouldn't be a Cambridge relation in respect of the changer).
But that may not be right either. Suppose that times are constituted by the events that happen at them. (A kind of Aristotelian view.) Suppose in 2004, and only in 2004, there is an intense flurry of excitement about Leibniz's correspondence with Masson. Then Leibniz stands in the relation of having caused an intense flurry of excitement in to the year 2004, but not to the year 2005. Causing is a non-Cambridge relation in respect of either relatum, and since years are constituted of the events that stand in the causing relation, it seems that this relation is non-Cambridge in respect of the year, too. But while Leibniz may have changed between 2004 and 2005 (e.g., in heaven, he may have come to a greater love of God), his being the cause of an intense flurry of excitement in 2004 but not in 2005 is not sufficient for change.
At this point, the unsatisfying state of affairs is that some relations imply change and some don't. Greenly occupying 2004 but not 2005 does imply change. Causing an intense flurry of excitement in 2004 but not 2005 does not imply change.
Interestingly, the relation of having caused an intense flurry of excitement in is actually a ternary relation. Thus, we might say that in 1716, Leibniz caused an intense flurry of excitement to happen in 2004 (viz., by writing the letter to Masson): it is a relation between a substance (Leibniz) and two times (1716 and 2004). And a difference between times in respect of the first temporal relatum (the one filled by 1716) does imply change, while a difference between times in respect of the second temporal relatum (the one filled by 2004) does not: if in 1715 Leibniz did not cause an intense flurry of excitement to happen in 2004, but in 1716 he did, then he changed between 1715 and 1716. This means that we can't simply distinguish between relations and say some give rise to change and some don't. For there are relations R such that R(x,t,u)&~R(x,t*,u) implies change in x but R(x,t,u)&~R(x,t,u*) does not. What we need is some way of saying in respect of which pair of relata the relation gives rise to change.
The presentist has a nice story here. She can say that the property of presently causing an intense flurry of excitement in 2004 is a non-Cambridge property, albeit a non-intrinsic one, and that Leibniz has this property at one time and doesn't have it at another. But the kind of B-theorist that I am interested in does not say that: she just has a ternary relation of ___ in ___ causing an intense flurry of excitement in ___.
Now, it is true that the presentist's story does make use of the notion of a non-Cambridge property, a difficult notion to explicate that probably has to be made primitive. Vaguely speaking, a non-Cambridge property is one that a thing has in part because of how it presently is. Maybe the B-theorist can also primitively talk about a relation that an entity stands in in part because of how the entity is at one of the temporal relata of that relation.
Maybe, though, instead of talking about what it is to change, we should just talk about what it is to change in respect of some relation. And that the B-theorist may be able to do.