change the background color of grid.arrange output

I am using grid.arrange from gridExtra package to put two graphs on one page and save it to a png file. I like to change the background colour of the final png file that is produced by grid.arrange. Is it possible? I was not able to come across any info.

grid.arrange(p1, p2, main=textGrob("CPU Util", gp=gpar(cex=1.2, fontface="bold", col="#990000")), ncol = 1, clip=TRUE)

Solution

Try setting the bg = argument to png()

library(gridExtra)
library(lattice)

png(bg = "wheat1")
    grid.arrange(xyplot(1:10~1:10, pch=16), xyplot(1:4~1:4, pch=16))
dev.off()

enter image description here