DrawNode inherited from Node => so DrawNode of course had setOpacity and setColor from Node.
Note:
In origin setOpacity it set _realOpacity, the value that the action Fade get to calculate for next opacity in step by step of action. Also the same with setColor and the value _realColor for action TintTo.
==> in order to run Fade / Tint correctly, you should call DrawNode::setOpacity / DrawNode::setColor before you custom any thing else after…