I would wager there aren't too many gigging musicians out there that absolutely don't care about the looks of the instrument. Most of them are in what's left of the punk crowd. There is a visual aesthetic to the performance of live music, and the instruments are part of that aesthetic.
That said, I bought my Sire P7 for its timeless traditional P-bass styling:
... and I certainly didn't mind the look of my primary before that, the TRB-1005:
My amp, not so much; I needed power and portability, and while I've always been impressed with how much amp Markbass packs into relatively small packages, the yellow on black aesthetic was never really my thing. But, I couldn't say no to an Italian-made CMD102P for $675. Most of the time, it hangs out behind a stage scrim with the band logo on it.
As for effects, I bought one based at least in part on its looks, but it's a bit more complicated. The pedal I own is the Walrus Audio Julianna, which I bought because I was initially drawn to the entrancing art of her older little sister, the Julia V2:
I was looking for "the last chorus" for my skinny-string board, which would free my CEB-3 to come home to the bass board. Julia, on looks alone, beat out pretty much everything else in the field, but I could never quite justify the cost for a
fairly basic chorus pedal. Enter her big sister:
The art is similar, but apparently a few people said Julia V2, while a
definite improvement over the V1's art, was turning too many guitarists into literal shoegazers. To keep the idea of V2's sea spirit while getting rid of the soul-searching stare, the artist put Julianna's arm over her eyes. Feature-wise, they added the tap tempo and stereo that I said I wished Julia had, and the ramp and drift features that I actually use, for not a terrible amount more than Julia cost new, so I could no longer say no to a Walrus chorus.