For spplot.points, parameter `at` not work

[Dongdong Kong]

spplot(meuse["dist"],
       at = seq(0, 1, .5),
       colorkey = list(
    right = list( # see ?levelplot in package trellis, argument colorkey:
        fun = draw.colorkey,
        args = list(
            key = list(
                at = seq(0, 1, .5), # colour breaks
                col = bpy.colors(11), # colours
                labels = list(
                    at = c(0, .2, .4, .6, .8, 1),
                    labels = c("0x", "20x", "40x", "60x", "80x", "100x")
                )
            )
        )
    )
))

Can I specify at which values colours change for spplot.points?