in the script plot(my_ogive_fq, xlab = "Total length (cm.)", ylab = "Proportion mature", col = c("blue", "red"), onlyOgive = TRUE) how do i change the color of the plot from gray to black? 
in the script
plot(my_ogive_fq, xlab = "Total length (cm.)", ylab = "Proportion mature", col = c("blue", "red"), onlyOgive = TRUE)
how do i change the color of the plot from gray to black?