CREDITS TO LAGOA WHO ORIGINALLY DISCOVERED THIS IN NBA 2K12
1 - Open any global using the NBA 2KX Mod Tool
2 - Export the texture that you will make black/white
(I picked the Full Padded Calf Sleeve)
3 - Open a Picture Editing Software and Open your texture
4 - Click Colorify it is located in Colors --> Colorify and click Custom Colors
5 - Select the G and pull it all the way to the left and do the same as well in the B
6 - Save the texture in DXT1 and generate Mipmaps
7 - Import it back to the global and enjoy
BEFORE
AFTER