NMS Mass Tools
Copy .PAK files to NMS Mass Tools folder.
Run All_Extractor.bat
Path: TEXTURES\UI\FRONTEND\ICONS\
Use Photoshop Scripting\Images to process folders.
References
How to edit .DDS Textures
NMS Mass Tools Collection - Nexus Mods
Getting Started - No Man's Sky Modding Wiki
NMS Modding Station - Nexus Mods
NMS Modding Station homepage