Karma asukla akrsnam yoginah trividham itaresam
In this verse, Patanjali tells us the karma of the yogi is neither white nor black; but the karma of the others is threefold.
Law of Karma states that for every action performed, there is another reaction created, which in turn produces a new counter action. Thus an endless chain of actions and reactions is produced; this increases the chain of material activities, keeping the performer in material bondage. Here, ‘action’ not only includes what you do, but also what you think. Thinking is mental karma. In fact, any deed, any thought that causes an effect is called karma.
For ordinary people, karma is threefold. In his book of “Light on the Yoga Sutras of Patanjali”, B.K.S. Iyengar explains that the three types of karma are white, black and mixed (or grey). White actions produce sattvic effects, black produce tamasic, while grey produces rajasic effect. But for advanced yogi, karma is not white (asukla) and not black (akrsnam). He has mastered all levels of inner process and has transcended sattva, rajas and tamas. His consciousness is always on the Divine, thus he no longer collects impressions, and his actions are free from the seed of reactions.
Swami Sivananda explains the threefold karma from a different point of view. The three types of karma are accumulated works (sanchita), the works that fructify (prarabdha), and the current works (agami or kriyamana). Sanchita is accumulated from the past; part of it can be seen as the character of a person, his tendencies and aptitudes, capacities, inclinations and desires, etc. Prarabdha is the portion of the past karma which is responsible for the present body. It is something like the amount on your current month’s credit card bill, which is already spent and you have to pay it back. Thus, prarabdha cannot be avoided or changed. Agami is the karma which is now being made for the future. Swami Sivananda says that karma is produced by desires and thoughts. As long as there are desires, there is karma. However, karma can be destroyed. By attaining knowledge of Brahman, sanchita karma is destroyed. By realizing that one is an instrument in the hands of Divine and one is silent witness of the actions of the senses and of the mind, agami can be destroyed. Gradually, one’s character, thoughts and actions are changed. As a result, he can rise to a high level to perfection and become a perfect yogi. At the stage, he is beyond virtue and vice, beyond gain and loss.