double click the .reg file to load the values into your register, this will add a new session named "Monokai" into your putty
remember to replace all the "***" in this reg file with your user id in /HKEY-USERS/, you could search "Putty" in folder /HKEY-USERS to see which is your current user id
** List of Color Schemes **
- Monokai from Sublime