No, dogs cannot see red. Dogs have dichromatic vision, which means they can see shades of blue and yellow, but not red or green. This is similar to how people with red-green color blindness see the world.
"keep the coyotes out... while wife walks the dog ..."
"No, dogs cannot see red."
I dare say SMOKEYDOG (nor his wife) never so much as intimated their dog even noticed the flashing LED's
He certainly never stated nor implied their dog saw red in the day or night!
SARG, you need research coyotes' vision - that 'fun fact' might prove pertinent. e.g. "Dogs see red as brown and green as shades of yellow." So, in point of fact, at night, your puppy will see brown 'Predator Eyes" flashing, right?
Saving you a bit of effort, I found "Coyotes have protanopia dichromacy, which means they have a limited color spectrum and are color blind . . ."
Something a hunter might know?
One aspect these sorts of 'arguments' ignore is that fact the DARKNESS is certainly kin to an ABSENCE OF LIGHT.
These devices take advantage of that fact and only 'flash' their (what most sapiens* see as red) lights after dark.
So, the question is not necessarily about the color (wavelength, actually) of the diodes as much as the (relative to darkness) intensity of their illumination - the contrast, if you will. And, likely the rate of the flashing combined with the simply 'unnatural phenomenon' these devices present to prey and predator alike.
e.g. Something lit up over there a bright, intense speck of (any color) light(s) seen 'out of the corner of (any creature's) eye' in an otherwise still evening on SmokeyDog's Farm.
Now, one need pay close attention to Googol (et al) AI responses because A.I. is in it's infancy. It can recognize a Daddy figure on sight, perhaps, but has yet to understand how one** is supposed to act. So, best to do a deeper dive and, a the very least, look at page two of the results before placing your bet(s).
* Sapiens translates to wise. So **** Sapiens are the wise sapiens. Who came up with that name for us? Why, we did!
** A 'daddy figure' that is.