Each of the 9 planets or the Navagrahas emit a cosmic energy on a particular frequency in the energy spectrum. This cosmic energy unleashed by the planets in seen by us in the form of colors. The vedas declare Prakriti or Nature to be God itself and anything that is produced by nature always has the god element within it.
How is it possible for a seed to just intake soil , air , water , sunlight and the right conditions to transform into juicy fruits or vegetables ? We humans never have possessed this kind of technology nor we ever will , because this simply is an act of Prakriti or Nature or GOD ! Similarly , the earth is a host of a wide variety of minerals , metals and rocks which are collectively known as Dhatu in Jyotisa and from these rocks are mined the various gemstones each having the same god particle within them. Vedic Astrology recommends using gemstones to correct and strengthen the cosmic radiations emitted by the grahas.