Is this actually dithering?

I have dabbled with some dithering algorithms and while this is way faster than my naive js implementations, this looks pretty bad

Yes it is dithering. Unusual dithering though - I don't see why it is coloured. Is this intended for printers?

The image gets de-saturated but the noise that's mixed in is colored. This looks like a mistake.

I think the noise is also way too 'soft'. At high frequencies it just becomes near-uniform gray so it barely affects the thresholding.