Instead of changing the helmet, lego could just paint the rest of the armor with the same color. The lighter tone of the helmet is already good for Boba's look from Mando
Wearable Boba Fett costume built from LEGO - The Brothers Brick | The Brothers Brick
Lego Boba Fett Costume | Boba Fett Costume and Prop Maker Community - The Dented Helmet
Disfraz de Boba Fett hecho con Lego - No Puedo Creer
LEGO® Star Wars™: Casco de Boba Fett™ 75277 | Star Wars™ | Oficial LEGO® Shop ES