Notes about the GMMP file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The GMMP file type is primarily associated with 'Windows Color System' by Microsoft Corporation. A GMMP targets a particular gamut mapping model, either one of the built-in baseline gamut mapping models, or a plug-in gamut mapping model. As with DMPs (CDMP file extension), a GMMP that targets a plug-in GMM must also specify a baseline gamut mapping model as a fallback.