Find Transparent Equivalent of Color in R (2 Examples)

This page shows how to determine the transparent version of a hex color code in the R programming language.

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Here’s how to do it:

Example Color & Add-On Packages

The first step is to create an exemplifying color object.

my_col <- "#1B98E0FF"                               # Define hex color code

We also need to install and load the scales package, in order to display our colors in R:

install.packages("scales")                          # Install & load scales
library("scales")

We can now use the show_col function to show our example color in RStudio:

show_col(my_col)                                    # Show color

As shown in Figure 1, the previously shown code has managed to create a plot displaying our example color in R.

Example 1: Convert Color Code into Transparent Version

In Example 1, I’ll illustrate how to determine the equivalent hex color code of our example color with a decreased alpha opacity of 0.2.

Have a look at the following R syntax:

my_col_alpha <- adjustcolor(my_col, alpha.f = 0.2)  # Create transparent color code
my_col_alpha                                        # Print new color code
# [1] "#1B98E033"

As you can see based on the previous output of the RStudio console, the transparent equivalent of our example color is the hex color code #1B98E033.

Let’s show this color in comparison to the original input color:

show_col(c(my_col, my_col_alpha))                   # Show original & transparent color

Figure 2 shows the output of the previous code: As you can see the new version of our color has a low opacity.

Example 2: Convert Color Code into Vector of Multiple Transparent Versions

Example 2 illustrates how to create a sequence of color codes with decreasing opacity.

For this, we can use a for-loop as shown below:

my_col_alpha_all <- character()                     # Create vector of color codes
for(i in 1:20) {
  my_col_alpha_all[i] <- adjustcolor(my_col, alpha.f = i / 20)
}

Let’s have a look at the output of the previous for-loop:

my_col_alpha_all                                    # Print vector of color codes
#  [1] "#1B98E00D" "#1B98E01A" "#1B98E026" "#1B98E033" "#1B98E040" "#1B98E04D" "#1B98E059" "#1B98E066" "#1B98E073"
# [10] "#1B98E080" "#1B98E08C" "#1B98E099" "#1B98E0A6" "#1B98E0B3" "#1B98E0BF" "#1B98E0CC" "#1B98E0D9" "#1B98E0E6"
# [19] "#1B98E0F2" "#1B98E0FF"

As you can see, we have created a vector containing 20 different color codes.

Let’s visualize these colors in R:

show_col(my_col_alpha_all)                          # Show all colors

As shown in Figure 3, the previous R code has created a graphic showing 20 different alpha versions of our input color and the corresponding hex color codes.

Video, Further Resources & Summary

Have a look at the following video that I have published on my YouTube channel. I show the R code of this tutorial in the video.

Furthermore, you might read the related articles on my website. I have published several articles already:

• Create Distinct Color Palette in R
• Extract Default Color Palette of ggplot2 R Package
• All R Programming Tutorials

Summary: This tutorial has shown how to get the color code of a given color with less alpha in R programming. If you have additional questions, don’t hesitate to let me know in the comments section.