Using Conditional Statements to Change the Color of Data Points

Question

I have a data set, which I have used to make a scatter plot and I would like to assign three different colors to the data points within three different regions, based on the

Answer 1

I like the cut approach:

set.seed(1)
x <- sample(1600)
col <- c("red", "black", "purple")
col <- col[cut(x, breaks=c(-Inf, 3, 1549, Inf))]