Or you could open the textures in paint.net and make them lighter yourself. I know, crazy idea, right?
been there, done that, but it will still remain the same for everyone else and everybody else still won't be wearing these in game because they just look wrong with every armor that a historical knight would wear with these helmets! I am not the only person who finds this annoying, in fact you have also commented on their darkness
Not only are they too dark, they are also HUGE. Every single one except the Gotland are ridiculous globes, and even the Gotland is slightly too large.
Surely if enough people see this as a problem it is better to just change them rather then having lots of people editing the textures themselves, I'm just trying to help and to see if others feel the same so we can get this finally changed for the better!