Most Helpful Guy
match your sandals to whichever color there is least of on the bikini.
if there is equal blue and white, then are there accents? sometimes there will be hints of color as accents. you can match your sandals to that accent color.
equal blue/white AND no accents? simple, see if the bikini is tied with strings. if so, choose sandals that are the color of the strings.
(matching by strings work because on a bikini, the strings are like a belt on regular clothes. proper fashion is to always match shoes, belt, and hat. -no matter what colors are in the outfit, these three should always match) so by matching sandals to strings you are keeping with this rule and will look great. :)
lmk if you have any further questions and enjoy the beach!