I'm not proud to admit this (as a scratch, competitive bowler), but yes - this has factored into my decision at times. Not all the time, but at times it has. Think about it - everyone makes good equipment, and everyone makes equipment that "fits" a certain ball motion. Given that I can get pretty much any ball motion I want from any manufacturer (or by using different layouts), then with all performance things being equal I am often persuaded by appearance in making my final choice.

Speaking of this, I asked a staff member of a certain ball company the other night why he selected a "plain" spare ball over another option from this manufacturer that looked much wilder and more interesting. He said that his ball driller recommended the plain option because otherwise he (the bowler) would pay too much attention to how the ball looks instead of the roll. I thought this was an interesting thing to hear. Of course, being a spare ball with no dynamic core he wouldn't get any difference in reaction between the two balls, but it was interesting to note how the more visually appealing ball didn't win out in this instance.

Reading this thread reminded me of a ball I purchased back around 1999 or 2000.

The pro-shop operator told me he had a [used] ball in mind for me, and when he showed it to me, my first impression was yuck! It was purple, and had pock marks and scratches and was very dull (and not because of sanding or OOB design). He said he would clean it up and I was reluctant, but trusted him, and if he thought it was a good match for my game (he had seen me throw), I was willing to try it.

That ball was (is) a Brunswick Command Zone. He did, in fact, clean it and polish it nicely, but more importantly, that ball is still effective and one of my favorites for it's performance, 14 years later.  It's kind of a "mini" skid-flip ball, at least in my hands.

Goes down the lane with very little movement, and then just before it reaches the pins it makes a very abrupt shift. It's not very many boards at all, but I can throw it accurately and still get it to hit at an angle.

Am still not a huge fan of purple balls, and this is not a favorite cause of it's appearance. But am glad I was able to overlook it's beat-up appearance when it was first introduced to me.