我想在shiny应用程序中，当datatable第二列的每个单元格的值等于dataframe第三列同一行的单元格的值时，更改其背景色。

## app.R ##
library(shiny)
library(shinydashboard)
library(DT)
comp<-structure(list(Source = c("dates1", "dates2", "dates3", "dates4", 
                                "dates5", "dates6", "dates7"), Counts = c(12L, 15L, 17L, 10L, 
                                                                          12L, 7L, 9L), Comparison = c(15, 15, 15, 15, 15, 15, 15), Difference = c(3, 
                                                                                                                                                   0, -2, 5, 3, 8, 6)), row.names = c(NA, -7L), class = "data.frame")

ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(),
  dashboardBody(
    datatableOutput("table")
  )
)

server <- function(input, output) {
  
  output$table<-renderDataTable({
    datatable(comp)
  })
}

shinyApp(ui, server)