Unreal UE4 - Niagara dark material looks black in preview.... But looks orange in the viewport, why?

Hi, i created a black smoke material for a Niagara emitter to create an after explosion effect, the explosion looks perfect inside Niagara´s viewport and the black smoke looks great… But when i use this effect in the world, Unreal viewport or any caracter BP, the black smoke looks dark orange……why? it should look the same inside Niagara and in Unreal vierport…. but colors are different, i haven´t had any problema with any other color… but black looks weird.

Even do i dont understand why a black color has a variance in UE viewport and Niagara preview, how you recommend me to make Niagara black smoke?