library(CatterPlots)
x <- -10:10
y <- -x^2 + 10
rainbowCats(x, y, yspread=0.05, xspread=0.05, ptsize=2, catshiftx=0.5, catshifty=-0.2, canvas=c(-0.5,1.5,-1,1.5))

library(devtools)
install_github("Gibbsdavidl/CatterPlots")

R CMD INSTALL CatterPlots

library(CatterPlots)
x <- -10:10
y <- -x^2 + 10
purr <- catplot(xs=x, ys=y, cat=3, catcolor='#000000FF')
cats(purr, -x, -y, cat=4, catcolor='#FF0000')

# for more fun ...
meow <- multicat(xs=x, ys=y, cat=c(1,2,3), catcolor=list('#33FCFF','#FF0000'), canvas=c(-0.1,1.1, -0.1, 1.1))
morecats(meow, x, 10*sin(x)+40, size=0.05, cat=c(4,5,6), catcolor=list('#0495EE','#EE7504'), type="line")

# random cats
meow <- multicat(xs=x, ys=rnorm(21),
                 cat=c(1,2,3,4,5,6,7,8,9,10),
                 catcolor=list('#33FCFF'),
                 canvas=c(-0.1,1.1, -0.1, 1.1),
                 xlab="some cats", ylab="other cats", main="Random Cats")