Absolutely. It's just harder to visualize the resultant waveform.
For example, two waves exactly 180 degrees out of phase with the same frequency and amplitude will give a resultant wave of zero. Whereas with different frequencies, you could still have a non-zero product even with a 180 degree phase difference.
Waves with different frequencies can interfere but their interference will not be pronounced.
To be pronounced, waves should be monochromatic and coherent.