Where exactly did I go wrong with this on/off script?

local on = false

script.Parent.MouseButton1Down:connect(onClicked)
    if not on then
        on = true
    elseif on then
        on = false
    end
end)

while on do 
    game.Workspace.Test4.Light1.BrickColor = BrickColor.new("Medium stone grey") 
    game.Workspace.Test4.Light2.BrickColor = BrickColor.new("Really red")  
    game.Workspace.Test4.Light3.BrickColor = BrickColor.new("Medium stone grey")
    game.Workspace.Test4.Light4.BrickColor = BrickColor.new("Really red")
	game.Workspace.Test4.Light5.BrickColor = BrickColor.new("Really red")
	game.Workspace.Test4.Light6.BrickColor = BrickColor.new("Really red")
    wait(1)
    game.Workspace.Test4.Light1.BrickColor = BrickColor.new("Really red") 
    game.Workspace.Test4.Light2.BrickColor = BrickColor.new("Medium stone grey")
    game.Workspace.Test4.Light3.BrickColor = BrickColor.new("Really red")
    game.Workspace.Test4.Light4.BrickColor = BrickColor.new("Medium stone grey")
	game.Workspace.Test4.Light5.BrickColor = BrickColor.new("Medium stone grey")
	game.Workspace.Test4.Light6.BrickColor = BrickColor.new("Medium stone grey")
    wait(1)
    game.Workspace.Test4.Light1.BrickColor = BrickColor.new("Medium stone grey") 
    game.Workspace.Test4.Light2.BrickColor = BrickColor.new("Medium stone grey") 
    game.Workspace.Test4.Light3.BrickColor = BrickColor.new("Medium stone grey")
    game.Workspace.Test4.Light4.BrickColor = BrickColor.new("Medium stone grey") 
	game.Workspace.Test4.Light5.BrickColor = BrickColor.new("Medium stone grey")
	game.Workspace.Test4.Light6.BrickColor = BrickColor.new("Medium stone grey")
    wait(1)
end

while not on do 
    game.Workspace.Test4.Light1.BrickColor = BrickColor.new("Medium stone grey") 
    game.Workspace.Test4.Light2.BrickColor = BrickColor.new("Medium stone grey")  
    game.Workspace.Test4.Light3.BrickColor = BrickColor.new("Medium stone grey")
    game.Workspace.Test4.Light4.BrickColor = BrickColor.new("Medium stone grey")
	game.Workspace.Test4.Light5.BrickColor = BrickColor.new("Medium stone grey")
	game.Workspace.Test4.Light6.BrickColor = BrickColor.new("Medium stone grey")
    wait()
end 

To start off, you have multiple while true do loops. When you run one of those loops, it'll keep running and never get past that loop unless you would use coroutine. Well, I have my way that may not be the most efficient, but always gets the job done. I'd make 3 scripts in total. One that would toggle the on/off, one that would be looping the on, and the last looping the off. Here's how it would look:

Toggle Script:

local on = false
OnScript = script.On -- Should be disabled by default
OffScript = script.Off -- Should be disabled by default

script.Parent.MouseButton1Down:connect(function() -- If this is a ClickDector, make it MouseClick
	if on == false then
		on = true
		OffScript.Disabled = true
		OnScript.Disabled = false
	else
		on = false
		OnScript.Disabled = true
		OffScript.Disabled = false
	end
end)

On Script: (Should be disabled by default)

Light1 = game.Workspace.Test4.Light1
Light2 = game.Workspace.Test4.Light2
Light3 = game.Workspace.Test4.Light3
Light4 = game.Workspace.Test4.Light4
Light5 = game.Workspace.Test4.Light5
Light6 = game.Workspace.Test4.Light6

while true do
	Light1.BrickColor = BrickColor.new("Medium stone grey")
	Light2.BrickColor = BrickColor.new("Really red")
	Light3.BrickColor = BrickColor.new("Medium stone grey")
	Light4.BrickColor = BrickColor.new("Really red")
	Light5.BrickColor = BrickColor.new("Really red")
	Light6.BrickColor = BrickColor.new("Really red")
	wait(1)
	Light1.BrickColor = BrickColor.new("Really red") 
	Light2.BrickColor = BrickColor.new("Medium stone grey")
	Light3.BrickColor = BrickColor.new("Really red")
	Light4.BrickColor = BrickColor.new("Medium stone grey")
	Light5.BrickColor = BrickColor.new("Medium stone grey")
	Light6.BrickColor = BrickColor.new("Medium stone grey")
	wait(1)
	Light1.BrickColor = BrickColor.new("Medium stone grey")
	Light2.BrickColor = BrickColor.new("Medium stone grey") 
	Light3.BrickColor = BrickColor.new("Medium stone grey")
	Light4.BrickColor = BrickColor.new("Medium stone grey") 
	Light5.BrickColor = BrickColor.new("Medium stone grey")
	Light6.BrickColor = BrickColor.new("Medium stone grey")
	wait(1)
end

Off script: (Should be disabled as default)

Light1 = game.Workspace.Test4.Light1
Light2 = game.Workspace.Test4.Light2
Light3 = game.Workspace.Test4.Light3
Light4 = game.Workspace.Test4.Light4
Light5 = game.Workspace.Test4.Light5
Light6 = game.Workspace.Test4.Light6

while wait() do
	Light1.BrickColor = BrickColor.new("Medium stone grey")
	Light2.BrickColor = BrickColor.new("Medium stone grey") 
	Light3.BrickColor = BrickColor.new("Medium stone grey")
	Light4.BrickColor = BrickColor.new("Medium stone grey") 
	Light5.BrickColor = BrickColor.new("Medium stone grey")
	Light6.BrickColor = BrickColor.new("Medium stone grey")
end