How to change the color of a RadioButton option depending on whether it is the correct choice?

I am currently developing an R Shiny App to train some new starters at our company in R. Using Shiny, I want to include multiple choice questions and options to test people on certain questions. For example, the question below:

Now, the cosmetic change I want to make is that when they click/tag the correct answer (Answer 1) that the correct answer (Answer 1) text changes to a green colour. Or vice versa, if the incorrect answer is selected that the colour turns red. I had added a 'show answer' button for more context why.

I have tried some things, but it is not working. Is there anyone who has an idea how to fix this?

The code is the following:

library(shiny)

ui <- fluidPage(
    
    mainPanel("What would happen if you ran 6- in the console? Make a guess!",
    radioButtons("question1", 
                 label = NULL, 
                 choiceNames  = list(HTML("+ sign"),
                                     HTML("6"),
                                     HTML("-6"),
                                     HTML("6-")),
                 choiceValues = list("text", "text", "text", "text"), 
                 width        = 500, 
                 selected     = character(0)),
    actionButton("answer_button_1", "Show Answer"),
    verbatimTextOutput("n_answer_text_1")
    )
    )

server <- function(input, output) {

        #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        # Answers of Question 1
        #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        n_ans_text_1 <- eventReactive(input$answer_button_1, {
            "ANSWER ANSWER"
        })
        
        #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        # Render the text of the answers
        #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        output$n_answer_text_1 <- renderText({n_ans_text_1()})

}

# Run the application 
shinyApp(ui = ui, server = server)

Create a data frame which contains the raw answers and also the via HTML formatted answers, e.g.

> choiceData
  choiceNames choiceValues                    choicesFormatted
1      + sign          ch1 <font color='green'> + sign </font>
2           5          ch2        <font color='red'> 5 </font>
3          -6          ch3       <font color='red'> -6 </font>
4          6-          ch4       <font color='red'> 6- </font>

Include an observeEvent on input$question1 (triggers if a choice is selected) containing an ifelse which collects the new choices from the data frame depending on what is input$question1 (if input$question1 is choiceValues, take the formatted choice, else the raw choice). Then use updateRadioButtons for providing the updated values on the radio buttons.

library(shiny)

choiceData <- data.frame(
  choiceNames = c("+ sign", "5", "-6", "6-"),
  choiceValues = paste0("ch", 1:4),
  choicesFormatted = c(HTML("<font color='green'>", "+ sign </font>"),
                       HTML("<font color='red'>", "5 </font>"),
                       HTML("<font color='red'>", "-6 </font>"),
                       HTML("<font color='red'>", "6- </font>")))

ui <- fluidPage(
  
  mainPanel("What would happen if you ran 6- in the console? Make a guess!",
            radioButtons("question1", 
                         label = NULL, 
                         choiceNames  = choiceData$choiceNames,
                         choiceValues = choiceData$choiceValues, 
                         width        = 500, 
                         selected     = character(0)),
            actionButton("answer_button_1", "Show Answer"),
            verbatimTextOutput("n_answer_text_1")
  )
)

# Define server logic required to draw a histogram
server <- function(input, output) {
  
  observeEvent(input$question1, {
    
    uchoiceNames <- ifelse(choiceData$choiceValues == input$question1, 
                           choiceData$choicesFormatted, 
                           choiceData$choiceNames) |> 
      lapply(HTML)
    
    updateRadioButtons(
      inputId = "question1",
      choiceNames  = uchoiceNames,
      choiceValues = choiceData$choiceValues,
      selected = input$question1
    )
  })
  
  #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  # Answers of Question 1
  #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  n_ans_text_1 <- eventReactive(input$answer_button_1, {
    "ANSWER ANSWER"
  })
  
  #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  # Render the text of the answers
  #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  output$n_answer_text_1 <- renderText({n_ans_text_1()})
  
}

# Run the application 
shinyApp(ui = ui, server = server)