Color dynamic points in plotly scatterplot permanently based on color argument

I have this shiny app and I want to color the points in the 3d scatterplot based on the date selected by giving them a speicific color every time and not a random color which will change when I hide and then bring them back again. But all my points are still blue

library(shiny)
library(tidyverse)
library(plotly)
library(dplyr)

df2<-structure(list(publicationDate = structure(c(18610, 18410, 18597, 
                                             18375, 18284), class = "Date"), x = c(8.593744, 10.341268, 11.454429, 
                                                                                   10.595986, 11.012522), y = c(4.2456923, 6.767409, 5.2631335, 
                                                                                                                6.5070715, 7.6513457), z = c(5.6303487, 8.002673, 6.332502, 8.773426, 
                                                                                                                                             8.604475), influentialCitationCount = c(98.2037608756666, 100, 
                                                                                                                                                                                     37.8052203199551, 99.6632051641875, 99.1018804378333)), row.names = c(NA, 

                                                                                                                                                                                                                                                           5L), class = "data.frame")
df2 <- df2[order(df2[, 1]), ]

ui <- fluidPage(
  titlePanel("3D Scatter Plot Visualization"),
  sidebarLayout(
    sidebarPanel(
      pickerInput(inputId = "selectedDates",
                  label = "Choose Dates:",
                  
                  choices = list(Dates = as.list(unique(df2$publicationDate)),PointColor = colors()[5]),
                  selected = unique(df2$publicationDate)[1],
                  multiple = TRUE,
                  options = list(
                    `actions-box` = TRUE,
                    `deselect-all-text` = "None...",
                    `select-all-text` = "Yeah, all !",
                    `none-selected-text` = "zero"
                  ))

    ),
    mainPanel(
      plotlyOutput(outputId = "scatterPlot3D")
      
    )
  )
)

server <- function(input, output) {
  output$scatterPlot3D <- renderPlotly({
    
    # Filter data based on selected topicLabels
    df2 <- df2[df2$publicationDate %in% input$selectedDates, ]
    
    
    # Create the 3D scatter plot with bolded hover text
    scatter3Dplot <- plot_ly(data = df2, x = ~x, y = ~y, z = ~z, color = ~publicationDate,
                             type = "scatter3d", mode = "markers",
                             marker = list(size = 3)
                             ) %>%
      layout(title = "3D Scatter Plot with Wrapped Title and Custom Popup by Date",
             scene = list(
               xaxis = list(title = "X Axis"),
               yaxis = list(title = "Y Axis"),
               zaxis = list(title = "Z Axis")
             )) %>%
      layout(legend = list(orientation = "h"),
             showlegend = FALSE)
    
    
    
    return(scatter3Dplot)
  })
  
}



# Component 3: A call to the `shinyApp` function
shinyApp(ui = ui, server = server)

Solution

As a first step create a custom color palette for your publication dates and assign the (unique) dates as names. I simply used the default ggplot2 colors. Second, to use the color palette in your plotly chart add them via the colors= attribute. Third, for the color mapping convert publicationDate to a character:

library(shiny)
library(shinyWidgets)
library(plotly)

colors <- scales::hue_pal()(length(unique(df2$publicationDate)))
names(colors) <- unique(df2$publicationDate)

ui <- fluidPage(
  titlePanel("3D Scatter Plot Visualization"),
  sidebarLayout(
    sidebarPanel(
      pickerInput(
        inputId = "selectedDates",
        label = "Choose Dates:",
        choices = list(Dates = as.list(unique(df2$publicationDate)), PointColor = colors()[5]),
        selected = unique(df2$publicationDate),
        multiple = TRUE,
        options = list(
          `actions-box` = TRUE,
          `deselect-all-text` = "None...",
          `select-all-text` = "Yeah, all !",
          `none-selected-text` = "zero"
        )
      )
    ),
    mainPanel(
      plotlyOutput(outputId = "scatterPlot3D")
    )
  )
)

server <- function(input, output) {
  output$scatterPlot3D <- renderPlotly({
    # Filter data based on selected topicLabels
    df2 <- df2[df2$publicationDate %in% input$selectedDates, ]

    # Create the 3D scatter plot with bolded hover text
    scatter3Dplot <- plot_ly(
      data = df2, x = ~x, y = ~y, z = ~z, color = ~ as.character(publicationDate),
      type = "scatter3d", mode = "markers",
      marker = list(
        size = 3
      ),
      colors = colors
    ) %>%
      layout(
        title = "3D Scatter Plot with Wrapped Title and Custom Popup by Date",
        scene = list(
          xaxis = list(title = "X Axis"),
          yaxis = list(title = "Y Axis"),
          zaxis = list(title = "Z Axis")
        )
      ) %>%
      layout(
        legend = list(orientation = "h"),
        showlegend = FALSE
      )

    return(scatter3Dplot)
  })
}



# Component 3: A call to the `shinyApp` function
shinyApp(ui = ui, server = server)
#> 
#> Listening on http://127.0.0.1:4889