Question about an certain icon border type

[Eagle XI]

Its there on many hero icons: Paladin, Archmage, etc.
That additional blue running along the standard gray frame.
I cant get that in Button Manager, is there an template for it i can show to the program or must be done manually during icon creation ?

 

[NhazUl]

It's not a texture layer, it's a model composed of particle emitters that appears when a hero has gained a level. You can find it under UI\Buttons\HeroLevel\HeroLevel.mdx.

If you want to change the textures, it uses UI\Buttons\HeroLevel\HeroLevel-Border.blp and UI\Buttons\HeroLevel\HeroLevel-Particle.blp.