create a
pattern so that it looks like it was intended to be that way.

Eric got that right! That's been my philosophy for years, only not stated so
formally. Mine is " Make it look like it's 'sposed to be that way." Say I am
almost finished with a desk top and put a horrible ding at one end. Stead of
starting all over, cut it out put in a nice enlay, do the same in same place at
the other end. No extra charge for the marquetry.
Maybe some narrow trim tiles sorta outlining the toilet and complimentary or
contrasting tiles inside?
A thing I once did in my showerstall in a similar situation, was buy some
close tiles, and randomly removed some tiles from the walls. then replaced
with some new and mixed new and old randomly in the empty space. It was a
subtle randomness, almost a pattern , and it looked like it was s'posed to be
that way.
yum yum toungy here and here and here and maybe even there