color.js

$(document).delegate("#mytable",'DOMSubtreeModified','DOMNodeInserted', function(event) {                                           
                    color()
                  });


function color(){
  $('#mytable td').each(function(){
    $(this).css({'background':'#CCC'});
  }) 
}

server.R

library(shiny)

shinyServer(function(input, output){
  data <- reactive({
    get(input$data)
  })
  output$mytable <- renderTable({data()})
})

ui.R

library(shiny)

data.options<-function(){
  set<-lsp(datasets)
  set.class<-sapply(seq(set), function(i){ class(get(set[i]))})
  set[set.class=="data.frame"] #|set.class=="matrix"
}

lsp <- function (package, all.names = FALSE, pattern) {
  package <- deparse(substitute(package))
  ls(pos = paste("package", package, sep = ":"), all.names = all.names, 
     pattern = pattern)
}

shinyUI(basicPage(
  includeScript('color.js'),
  selectInput("data","Data Set", data.options()),  
  tableOutput('mytable')
))