DxO officially stopped selling and supporting version 3.0 over a decade ago.
Users with original retail keys can often still use them, though online activation servers for the Nik-era software may no longer be active. Nik Software Color Efex Pro 3.0 Serial Number
Here is a blog post covering the current status of Color Efex Pro 3.0 and the legitimate ways to use the software today. The Legacy of Nik Color Efex Pro 3.0: Is It Still Relevant? DxO officially stopped selling and supporting version 3
The serial number is a password you can share freely; it is personal to your purchase and should be kept secure. The Legacy of Nik Color Efex Pro 3
Color Efex Pro 3.0 was discontinued years ago after Nik Software was acquired first by Google and then by .
Q: Can I use Nik Software Color Efex Pro 3.0 with other image editing software? A: The plugin is designed for Adobe Photoshop and Lightroom, but may be compatible with other image editing software.