Nikon UK published this notice regarding the compatibility of the latest Nik Color Efex Pro version with Nikon Capture NX 2 software (Google purchased Nik software in September 2012):
Shortly after the acquisition of NikSoftware by Google in September 2012, Nik ended sales of the Color Efex Pro plug-in for Nikon Capture software.
From the end of January 2013, Nikon Europe no longer distribute Nik Color Efex Pro for Capture NX 2 and it is no longer available from our online sales site. However, should you be a current user of Color Efex Pro, you can of course continue to use the plug-in with Capture NX 2. Please refer to the table below for version compatibility.
Nikon Software version | Nik Color Efex Pro version |
Nikon software is not compatible | nik Color Efex Pro 4.0 |
Capture NX 2.3.0 or later | nik Color Efex Pro 3.0 64 Bit version for Capture NX2 |
Capture NX 2.0.0-2.2.8 | nik Color Efex Pro 3.0 for Capture NX2 |
Capture NX 1.2 or later / Capture NX 2 | nik Color Efex Pro 2.0 for Capture NX |
Capture 4.1 or later | nik Color Efex Pro 2.0 for Capture 4 |