im sorry, i thought the bios image could be downloaded from a ROM site. i got one now, thank you for the help

when i search game boy color bios and download the ROM the files wont open in gambatte so thats where im getting confused. do i need a .gb file or something else?

im confused, is there something specific i need to look up besides ROM? everything i download cant be opened by Gambatte, do i need a specific file type?