Summer time is time for sandals. Lots of people think their feet are ugly (including me) and a lot want to wear nail polish, because they think, their feet are prettier painted.
If you want pretty feet in your pretty sandals, I have a piece of advice.
DO NOT paint your toenails with a bright red, blue, pink or whatever colour. Paint your toenails with a nude or rosa colour. Bright colours will draw attention to your feet. Nude or rosa will blend in with your skin. I use a base coat from a french manicure set.