The Great Sage
The Storyteller
Dogs have dichromatic vision while humans have trichromatic vision. This means that dogs see colour just about as well as a human with red/green colourblindness.
Dogs have more 'rods' in their eyes than we do, which give them better night vision and a better ability to track moving targets compared to humans. Additionally, dog eyes are (usually) set farther apart than a human's which gives them less 'binocular' vision (less ability to focus on something in front of them) and a wider peripheral vision.
tl;dr: Dogs see colour, just not as much as a 'regular' human.
Dogs have more 'rods' in their eyes than we do, which give them better night vision and a better ability to track moving targets compared to humans. Additionally, dog eyes are (usually) set farther apart than a human's which gives them less 'binocular' vision (less ability to focus on something in front of them) and a wider peripheral vision.
tl;dr: Dogs see colour, just not as much as a 'regular' human.