Several countries have a license from Raufoss/Nammo to produce their .50 Multi-purpose design. FN, for example, does and has their own, separate MP design. Differences are the internal construction of the bullet.
FN’s Silver/Green tip (reverse of US Mk211) is their own HEPI design, Silver/Yellow is the APEI169, which is the Nammo design built by FN.
Several countries use green as a tip color code, the original Nammo code for example, early US, France, etc.
Current US code is Green/White, was previously Green/Silver
Green/Red is the Multi-Purpose Tracer.
White/Yellow is Nammo production for Sweden.