What do the different LED colour lights mean on the Cronus Zen?

The LED “eyes” colours will vary depending on the GamePack or GPC Script you’re using.

The general rule of thumb is, for TaylorDrift21 scripts:

Blue = Primary Weapon (Your AR, LMG etc)
Red = Secondary Weapon (Your Pistol, SMG etc)
Green = Profile 3 often used for Ground Loot pool.