Consensual green on green damage, especially to deny a resource to the enemy, or, for example, asking a friendly to ram between you and an enemy locked in boarding action to prevent you from losing, is ok.  Nonconsensual green on green is not ok.   Bear in mind that consensual or not, doing too much green damage will cause you to run afoul of the automated systems, so use consensual green on green damage frugally.
    • Like