If I'm picking out of a crowd, or picking a breed, yes, looks matter. Sarama attracted me at first with her looks . . . had she been a plain yellow mutt, I would have walked by. On the other hand, I was not, at that exact moment, looking for a dog. But unless someone had pointed at a plain yellow mutt and said, "that's the dog for you!" I probably would never look twice. Sarama was so close to my mental image of what a perfect dog for me would LOOK like that I had to stop and ask about her . . . and it turned out that she was also very close to what the perfect dog for me would ACT like, so it was a perfect match.
I like prick or semi-prick ears, rough coats, and to be honest, flashy, funky colors . . . bring on the merles, the brindles, the ticked, the heavily bi-color, the exotic blue . . . I love it.
That said, I'd been looking at standard poodles, which have neither the coat nor the ears (though they have some rather cool colors, love the cafe au lait and the red) so looks isn't the only thing. But I grew up with standards, and if their looks aren't my "dream" they are wonderful dogs. I knew I'd be happy with a standard. And I was looking at breeders who produced the colors I liked, even if I'd decided that the only colors I would turn down on an otherwise good match where white or cream (too hard to keep clean). Of course, then I met Sarama . . .
Breed rescue is different. Docket is red, which is my least favorite of the cardigan colors. He's very lightly built, and I like the stocky look of the cardis (though Docket may have fewer problems for being so light). His coat is the smoothest I've seen on any corgi. But he's a rescue, he came as he is, and he was picked out as a good match, and he is a good match. So I have no compliants.
I guess looks get my attention, but aren't the deciding factor. My favorite breeds are all over the map in appearence. I see a dog I like the looks of, I want to know more, either about the individual or the breed. But if that dog/breed is not tempermentally a good match, I don't keep wanting one for the looks. If/when I buy from a breeder, I may make a color preference known in the "all things being equal" sense, but not as a requirement! Getting the right dog is more important than the color, or any other cosmetic feature.
That said, there is one appearence thing that does matter, and would be a total turn off, and that would foster but not adopt. That's "funny" looking, aka unsound, dogs. If the dog isn't put together right I don't want it. By that I don't mean conformation in a show sense (Docket is a horrible Cardigan) but basic structure in a healthy dog sense (which by the naked eye Docket passes with flying colors). Its not just that I don't want an unhealthy dog, its that I find poorly constructed animals to be, well, displeasing to look at. Its not their fault, but I wouldn't want one around. Those GSDs with the awful hips not only horrify me for health reasons, they actally make me cringe. It looks so awful.