Emissive Color on sprite sheet

I have a sprite sheet with a guy running. I want his visor to glow. I can extract the sprites and create a color mask to use in a material so specify the location and glow. The problem is that I now have to do this for over a hundred sprites which will result in over a hundred materials, one for each sprite.
This seems a long shot but how can I specify that the visor must glow no matter its location?

Manager to get a work around. In paint editing tool copied the sprite sheet and erased everything except the visor. So on the original is the complete character and on the modified is only the visor. But I’m not packing the sprites close together. They are all on a 32x32 texture.
When I now import the sheets and then extract the sprites instead of “Auto” I select “Grid”, in Cell Height and Width I enter 32. Then on the character BP I duplicate it’s flipbook and on the new one I use the modified sprites and move the new flipbook 1 unit in front of the other. Now I have to sprite sheets overlapping. The original with its own material and the modified with the glowing material. When playing only the visor glows while the characters head bobs around : )