Open-source Lightroom alternative with built-in color modules similar to Color Efex Pro.
No—the last standalone version was part of Google’s Nik Collection (2016). DxO now sells Nik Collection 6 or 7, which includes Color Efex Pro as a core component, fully updated for modern cameras and operating systems. Color Efex Pro 5 Activation Key
is a professional photo editing software plugin developed by DxO (which acquired Google's Nik Collection, of which Color Efex Pro was a part). The current version as of my knowledge is included in the Nik Collection by DxO (e.g., Nik Collection 6 or 7), not a standalone "Color Efex Pro 5" release. Nik Collection 6 or 7)