It used to be that red and pink didn't "go" together. Orange and green? Unheard of. If colors clashed it was a bad thing. And now, just as all the old rules about fashion seem to be broken regularly by the most stylish among us, this rule is on the outs too. I'm increasingly seeing brown and mint, purple and red, ochre and orange, and it all looks great. Since it's summer, and clean, bright colors tend to rule, why not try orange and pink, or turquoise and yellow? Once fall is upon us, soften things and add some pastels; pink and mustard sound alarming but are so fresh and unusually beautiful, as are lavender paired with shades of green or red. Go with whatever color mood strikes, there are no rules anymore.
Photo from style.com: Dries Van Noten S/S '15, J.W. Anderson pre-fall '15, Marc by Marc Jacobs fall '15 RTW, Valentino pre-fall '15.