Game Boy and Game Boy Color dumps are .gb and .gbc. They share a header layout. The checksum byte at offset 0x014D is computed from the bytes at 0x0134 through 0x014C, which include the title. A translation that rewrites the title and forgets that byte will boot on some emulators and lock on hardware or on a strict core. Rom Patcher JS includes a header-checksum fix for this. I turn it on when the patch is known to edit the title and the result refuses to boot. I do not turn it on as a ritual for every IPS.
Color is not cosmetic. A GBC-only game sets the CGB flag in the header. A monochrome dump is a different file. Dual-mode games exist, and the readme should say which dump it hashed. An IPS of a Japanese GBC translation applied to a US .gb of a different revision will write something that is not the release. Because IPS has no source CRC, the button can still say finished. BPS releases in this scene are the ones that catch the mistake.
Representative work is translations and color hacks, shipped as IPS from older sites and sometimes as BPS now. I am not hosting those files. The author's page is the download. This page is the header rule and the extension rule. Save files are small SRAM and are not rewritten by a ROM patch unless the project says it relocated the save. That claim belongs in the project readme, not in a guess here.
Related pages: IPS, BPS, and the GBA page if the file is actually .gba. The extensions are not interchangeable.
