For an utmost summery all-day outfit go for white on white. No colour is more summery and fresh than white (and all hues of it), so when you decide to wear white colour from head to toe it results in a minimal and high-impact look. In this post I'm wearing Zara culotte pants, top and pearls. My gladiator sandals are from a leather shop.
Zara- cami top (you can find it here)
Gladiator sandals- (you can find them here)