Using ifelse within mutate and handling NA's

thanks for your time.

I have a question about using ifelse within the mutate function. ifelse is from base R, while mutate is from the dplyr package.

My question is about how ifelse handles NA values.

I have two character vectors: example_character_vector contains some words and occasional NA values while the other vector, color_indicator, contains only the words Green, Yellow, and Red.

I want to mutate my dataframe example_data_frame to create a new override_color_indicator variable that converts some of the yellows to greens depending on a condition in the example_character_vector.

Example data:

example_character_vector <- c("Basic", NA, "Full", "None", NA, "None", 
NA)
color_indicator <- c("Green", "Green", "Yellow", "Yellow", "Yellow", 
"Red", "Red")

example_data_frame <- data.frame(example_character_vector,
                                color_indicator)

This example_data_frame looks like so:

  example_character_vector color_indicator
1                    Basic           Green
2                     <NA>           Green
3                     Full          Yellow
4                     None          Yellow
5                     <NA>          Yellow
6                     None             Red
7                     <NA>             Red

I am using nested ifelse statements within mutate to create a new column called override_color_indicator.

If color_indicator is yellow and the example_character_vector contains the word "Full", I want the override_color_indicator to be Green (this is a special case within my data). Otherwise, I would like the override_color_indicator to be exactly the same as the color_indicator.

Here is my mutate:

example_data_frame <- example_data_frame %>% 
  mutate(override_color_indicator = 
          ifelse(color_indicator == "Green",
                 "Green",
            ifelse(color_indicator == "Yellow" & 
                          str_detect(example_character_vector, "Full"),
                   "Green",
                      ifelse(color_indicator == "Yellow" & 
                        !str_detect(example_character_vector, "Full") |
                             color_indicator == "Yellow" & 
                        is.na(character_vector),
                             "Yellow",
                             "Red"))))

(Apologies for the formatting - I tried to format this the best I could for Stack Overflow.)

This above code produces this dataframe:

  example_character_vector color_indicator override_color_indicator
1                    Basic           Green                    Green
2                     <NA>           Green                    Green
3                     Full          Yellow                    Green
4                     None          Yellow                   Yellow
5                     <NA>          Yellow                     <NA>
6                     None             Red                      Red
7                     <NA>             Red                      Red

My problem here is that in line 5, an NA is introduced in the override_color_indicator color. Instead of an NA, I would like it be "Yellow".

For clarity, this is my desired dataframe:

  example_character_vector color_indicator override_color_indicator
1                    Basic           Green                    Green
2                     <NA>           Green                    Green
3                     Full          Yellow                    Green
4                     None          Yellow                   Yellow
5                     <NA>          Yellow                   Yellow
6                     None             Red                      Red
7                     <NA>             Red                      Red

I've looked quite a bit for an answer, and couldn't find one anywhere. I could just create a workaround and go back and manually assign the entries to Yellow, but I don't love that option from a programmatic standpoint.

Also, I'm just kind of curious as to why this behavior happens. I've ran into this problem a few times now.

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Thanks for your time!