A Young's double-slit set-up is lit by white light that contains every wavelength between $400\ \text{nm}$ and $700\ \text{nm}$. A detector at a point P on the screen finds that the waves from the two slits arrive with a path difference of $1350\ \text{nm}$. Exactly one wavelength of this white light is missing from the light that the detector receives at P, because the waves cancel there. Which wavelength is it?