So if a completely colour blind (who can't tell any colour just brightness) will see the filtered image, but that image should be like subtle a change in the depth.
Sounds a little weird to me.
Color blind people see two channels (different causes for color blindness select different channels). Very few people can see 4 daylight channels (google "tetrachromat"). IIRC there is also a one-channel color blindness (at least theoretically) but it is ultra rare.
Now, what these glasses probably do (video won't work for me, can't see if they give a description), is that the filters make sure you see three different channels among your 4 input ones (2 eyes * 2 channels). It doesn't necessarily give a depth effect - more like a semi-transparent overlay saying "this greenred here is actually green" or "this greenred here is actually red".
And, yes - these filters necessarily select one (or two) channels which normal people can't actually see.
[0] In print you also add a Black (K) because it makes life easier, and because CMY subtraction dynamic range is harder to get right.
[1] there's another channel for darkness optimized for moonlight, which is not one of the daylight three.
As I understand it, people with mild red-green color blindness have trouble seeing color because the sensitivity range of their red/green photo sensitive cells overlap too much.
The filter in the glasses cuts out a portion of the red/green spectra, so that the overlapping is reduced. That makes the red photo sensitive cells receive only the deeply red light, and vice versa, creating better color channel separation.
