No, actually canines have the abilities to see quite a few colors. Wolves see more color than dogs and fox. I know dogs can see orange, green, white, black, grey, purple, brown, and orange. (not sure about orange)
Oh yea, they can see the entire spectrum in hues of dim yellows greys and blues, some dark brown and orangey colors, while some colors can reach a purple-ish tone but don't go to the actual color purple 8D
Basically, dogs almost never see in grey. The color green is interpreted as grey, but everything else is a dull color of yellow-ish or blue-ish shades 8D extending to cream and light blue to dark brown and black.
Well, not always. It depends on if you assert your authority over them or not, but even then they won't always prefer the one that tends to them most compared to the rest of the family. Take it as the dogs in my family, we have 4. Brett, Bailey, Cassie (all Shih Tzus), and Chancey (Cockapoo). Chancey prefers my mom, who mainly takes care of them when she is home, but everyone else takes turns when she isn't. Brett likes me the best, Bailey likes my dad the best even though he's never around, and we dunno about Cassie because we just brought her home today :3