How do I make a clickable lightbar, what am I doing wrong?

You never coded it to turn off LOL.

Here is a version of the script that uses a variable to determine if the lights are on or off, and breaks the loop of the code ran by the last trigger of the event to stop the lights.

WARNING CODE NOT TESTED

local lightBar = script.Parent
local blue = lightBar.BlueLight
local blue1 = lightBar.BlueLight1
local red = lightBar.RedLight
local red1 = lightBar.RedLight1
local red2 = lightBar.RedLight2
-- NEW STUFF
local OnorOff= "Off"



local function turnOn(part)
    part.Material = Enum.Material.Neon
    part.SurfaceLight.Enabled = true
end

local function turnOff(part)
    part.Material = Enum.Material.Plastic
    part.SurfaceLight.Enabled = false
end

 local function onClicked(player)
if OnorOff == "Off" then
    OnorOff =="On"
    while true do

    if OnorOff =="On" then
    turnOn(blue)
    turnOn(blue1)
    turnOff(red)
    turnOff(red1)
    turnOff(red2)
    wait(0.5)
    turnOn(red)
    turnOn(red1)
    turnOn(red2)
    turnOff(blue)
    turnOff(blue1)
    wait(0.5)
    else
    break
  end

end
else
OnorOff = "Off"

end

script.Parent.ClickDetector.MouseClick:connect(onClicked)