Blinking light doesn't make an Action

I pretty much finished a tutorial here: Although not part of the tutorial, I want to make the red light on the robot’s chest blink on and off through the whole animation. I can manually change two nodes from red to white and insert the frames into the timeline from the nodes themselves. But this would take a long time to go through the whole animation like this. And no Action is created. In the tutorial, I used the NLA editior for repeating a walk action. Is there a way I can copy and paste or otherwise speed up the process of turning the light from red to white and back to red for the duration of the animation?

Blend file:

You just make the key frame curve extrapolation cyclic. Is that what you are looking for? shift e
Yes you can copy and past Ctrl c and ctrl v
And you can shift d and duplicate key frames.

Yeah. In the Dope Sheet editor. Very simple. I duplicated the frames across the whole length of the video. I’ve been working in the NLA so much, I didn’t think of using the dope sheet editor. I would have responded earlier, but I’m not getting notified via email about threads I start.

Thanks for responding.