Simply drag the .dds file into your "Data/Textures/Scorptech/Readius" Folder, and you're done :D

This won't change the pip boy color, or the status menu for those check here

Status menu:
www.nexusmods.com/newvegas/mods/34720

Pip Boy Color:
http://www.nexusmods.com/newvegas/images/16807/?