I am currently in the process of designing a portfolio to manage investments. While such programs are not best plastered over the internet, a few basic concepts about plotting can be displayed.  For example, I have created a rather appealing plot, which demonstrates how to plot series of multiple images in a single plot, shown below:

Code is below, including my process to detrend the data. The critical lines are in bold, highlighting the fact that you can use sample(colors()) to select from the body of colors at random. This is useful when you may have to generate many plots, potentially without greatly detailed manual supervision, and you are not demanding publication-quality color selection (which is plausible for personal investigative use).

#after obtaining closing prices, you should make sure you clean your inputs. Ensure you know why there are NA’s, or you will make a critical error of omission.

closeprice<-log(closeprice)
data<-closeprice[is.finite(rowSums(closeprice)),]

#first-difference

data<-diff(data, lag=1, differences=1)
data<-na.omit(data)

#Check for any remaining trends in data over and above the natural cyclical or time-trending motion of the stocks!
#Detrend based off of the bond, a necessary part of even a basic CAPM portfolio
xhat<-lm(data$TYX.Close~1)$coefficients
detrended<-data-xhat #also, norm.
plot(index(detrended),detrended[,1],type=”l”)
for(n in 2:N){

lines(index(detrended),detrended[,n], col=sample(colors(),size=1))

}