The only time I ever gave a shit about cage aesthetics was when I got my Aussie flag ones for the TT bike for some LOLs. My old TT bike has been runing a cheap-as-shit black plastic cage forever. Proper Halfords Special deal from some used bike I bought 20 years ago. :)
Black cages are vinyl covered and make fewer marks on stainless steel too. Dunno what the obsession with silver bottle cages is personally.