See if this helps clarify things:
1 - Moissanite
is natively a 'faint tint' color stone- K-N for typical center stone sizes.
Thus the reason for enhancements, since typical diamond purchases are H color.
2 - Forever Brilliant
- the tinting is masked with a quartz film, softer than emerald, applied to the back of the stone.
A 1ct round improves 1 color grade (i.e. K->J). The color cancellation reduces the green and yellow, but appears to create/add grey as a result. No independent certification of the final color.
3 - Amora Enhanced Moissanite
- an atomic level improvement where nothing is added to the stone, and which addresses the true source of the tinting - broken molecular bonds.
After treatment the crystal is natively improved. Typically, hardness is increased by 1.5% (University testing), and color is improved 3-4 color grades.
Most larger rounds improve from K/L -> H color. Amora enhanced come with an independent color certification to verify the color improvement.
Thats the simplified version of things