Beam does not change color thru script?

--[[i am attempting to make a beam change color thru script but it does not allow me to do so.
this is how the script looks like:
]]
while wait()do
if game.Lighting.ClockTime>=18 then
game.Workspace.Clouds.Parts.Beam.Color=Color3.new(190,180,175)

if game.Lighting.ClockTime>=18.3 then
game.Workspace.Clouds.Parts.Beam.Color=Color3.new(120,150,110)

if game.Lighting.ClockTime>=19 then
game.Workspace.Clouds.Parts.Beam.Color=Color3.new(65,60,60)

if game.Lighting.ClockTime>=19.3 then
game.Workspace.Clouds.Parts.Beam.Color=Color3.new(0,0,0)

if game.Lighting.ClockTime>=4 then
game.Workspace.Clouds.Parts.Beam.Color=Color3.new(65,60,60)

if game.Lighting.ClockTime>=5 then
game.Workspace.Clouds.Parts.Beam.Color=Color3.new(120,150,110)

if game.Lighting.ClockTime>=6 then
game.Workspace.Clouds.Parts.Beam.Color=Color3.new(190,180,175)

end
end
end
end
end
end
end
end

-- is it from the script or the property is not allowed to change while in game at all?