While practicing such meditation, many people see Colors more often in the beginning. Some others even sense unfamiliar sensations or visions later on.
Reason behind why we see COLORS in the MEDITATION
In a healthy body, the five elements are maintained in balance with an equilibrium. When the body is not in balance, then it will try to attain balance by eliminating excess elements and taking in the lacking elements. Therefore all the disorders or imbalances in the body arise because of no harmony of the five elements in the body.
The Indriyas are: 5 sense organs (nose, tongue, skin, eyes and ears), 5 action organs (hands, vocal cords, genitals, feet and anus) and the mind.
The connection between the Five Elements, Indriyas and Chakras
Role in Existence and Sensation
Solidity in existence and Smell in sensation
Force of attraction in existence and Taste in sensation
Energy in existence and Sight in sensation
Movement in existence and Touch in sensation
Space and Hearing
For example if we see blue color, then it indicates that the blockages are clearing in the throat chakra, as the Sky/Ether element in the body is getting rejuvenated.
It is strongly recommended by many great Spiritual Masters not to do so, if our goal is to realize the Truth. Because they are the diversions which weakens the intensity of the meditation and obstructs not to touch the absolute Silence, as a Truth Seeker always wish to know and experience the Truth which is the absolute Silence or Emptiness.
"Do not pay attention to whatever you visualize in your mediation, to go beyond and experience the Emptiness, the absolute Silence".
~ Ramana Maharshi
So that you accept it and pave path to move to the further level rather than getting distracted.