In western spiritual traditions we find the terms 'white magic' and 'black magic'. These traditions encourage analytical understanding and use ritualistic mental tools to achieve that understanding. Whether one uses the tools and rituals intended to heal or harm determines whether it is white or black magic.
Although a psychic can use external rituals, the focus is on the mind of the psychic. We can't judge a psychic to be a black or white psychic depending on the tools he or she uses.
But, if we want to nitpick, we can take a look at what kinds of energies the psychic most uses and deals with. If we look at it this way, a white psychic is a psychic who predominantly uses 'white' or 'light' energies. (Of course, we can use any other description that we see fit as well, such as 'nature psychic', 'sound psychic', 'elemental psychic' etc.)
I would have to stress that 'white psychic' does not mean 'good psychic'. A person using the color 'white' and 'lightness' can be a healer who offers psychic energy to those in need. A white psychic can be an instructive teacher or a comforter.
Unfortunately, a white psychic can also behave like a kid with a hammer to whom everything looks like a nail. White energy is one type of energy, one kind of tool to use - and there are many others as well. A common mistake of white psychics is to overconcentrate energy (causing distress or worse) or to offer comfort when conflict would give a greater opportunity for spiritual growth.