Yes it is possible, but your idea is slightly wrong, it is not the opposite frequency, but exactly the same frequency but 180° (or half a wavelength) out of phase, so that a peak of one light wave would coincide with a trough of another light wave. This same effect can be seen on soap bubbles, where certain colours are being 'cancelled' leaving others, by the reflection off the top surface being out of phase with the reflection of the bottom surface. The two problems are that light reflected off an object is rarely one colour, and so is more than one frequency of light, and would therefor need very complicated apparatus to make sure every colour is in fact completely cancelled. also it would not make something invisible any more than something with no light reflecting off it is invisible. It would just appear black.