How to make a brighter texture for lightbar?

Hi, I'm trying to make some blue lights but I can't ... i tried finding some lightbar in the resources section and there's no one like the one I want ...

I do not know what factors influence so that a light flashes like the one I am going to put next .. can anyone tell me wich stuffs make the lights bright like that? (the next pic).

my idea is to make an object (led light) in this way

but that flashes like this image below,

i tried to make one but the light does not bright even a half-meter, was very opaque it has no brightness even if it has the visualsettings that it works with other vehicle mods ...
How could I do it? Does anyone of you have any texture that you know flashes like this? Could you pass it to me?

or how should I make the texture image?

thanks since now.