Regarding the hybrid backup:
You can use any sync tool for this purpose (e.g. built-in robocopy in Windows) to Sync Q:\Dropbox\Documents_encrypted with C:\User\...\Documents_decrypted
Regarding the green font:
Actually the file is still encrypted on the local folder - but with Windows' EFS instead of Boxcryptor. The Encrypting File System (EFS) is a windows feature that provides file system-level encryption. EFS was introduced with Windows 2000.
If you copy or move a file from the Boxcryptor Drive to another location on Windows 7, Windows Explorer is applying the Encrypted attribute of the source file also to the target file. The consequence is that the target file will be encrypted by Windows with EFS. Note that this only applies to Windows Explorer. If you copy a file e.g. using the command line, the Encrypted attribute is not set on the target.
We recommend to disable EFS if you don't need it and updated our installer to disable it for the user if he wants to. We have more information about Boxcryptor and EFS in our documentation: