Durga is worshipped in different forms. She is a form of "Shakti". The evolution of Shri Maha Saraswati, Shri Maha Laxmi and Shri Mahakali (the 3 main forms of "Shakti") took place from Shri Brahma, Shri Vishnu and Shri Mahesh respectively. Each of these 3 deities gave rise to 3 more forms and hence in all, these 9 forms together are known as Nav-Durga. .
Actually each Form in Nav Durga represents her special characteristic as per her guna which is in reference with color of their vestments i.e. red, yellow, blue, violet, green, orange, indigo, Grey and pink. Parvati represents white color vestments as white is combination of all colors that is why she is known as trigunatmika, combination of all gunas. Science says when white light goes from rarer (upper lokas like heaven) to denser medium (lower lokas like earth) it transforms to different colors.
If density variation is less, then three colors are formed i.e. Red, Yellow and Blue, now the three primary colors represents Mahalakshmi or Mahismardini(Red), Mahasarswati or Shumbh-Nishumbh Vinashni(Yellow) and Mahakali or Madhukaitabh Vibhanjani(Blue), the Goddesses are none other than the powers of trinity. Further these splits to nine colors as their wavelength exceeds and forms above mentioned nine colors of Nav Durga i.e. now Shailputri or Hemavati who is Goddess as Nature represents green color, Brahmacharini represents devotion i.e. indigo color, Chandraghanta reperesents beauty i.e. pink, Kushmanda represents beginning i.e. violet, Skandmata represents hard worker i.e. yellow, Katyani represents courage i.e. orange, Kaalraatri represents illusion i.e. blue, Mahagauri represents purity i.e. Red, Sidhidhaatri represents granter i.e. grey.more..
She is a daughter of Himalaya and first among nine Durgas. In previous birth she was the daughter of Daksha. Her name was Sati - Bhavani. I.e. the wife of Shiv. more..
The second Durga Shakti is Brahamcharini. Brahma that is who observes panance and good conduct. Here "Brahma" means "Tapa". The idol of this Goddess is very gorgeous. more..
The name of third Shakti is Chandraghanta. There is a half-circular moon in her forehead. She is charmful and bright. She is Golden colour. more..
Name of fourth Durga is Kushmanda. The Shakti creates egg. I.e. Universe by mere laughing she resides in solar systems.more..
Fifth name of Durga is "Skanda Mata". The daughter of Himalaya, after observing penance got married with Shiva. She had a son named "Skanda." more..
Sixth Durga is Katyayani. The son of "Kat" as "Katya". Rishi Katyayan born in this "Katya" linege. Katyayan had observed penance with a desire to get paramba as his daughter. As a result she took birth as a daughter of Katyayan. more..
Seventh Durga is Kalratri. She is black like night. Durga hairs are unlocked. She has put on neckles shining like lightning. She has three eyes which are round like universe. Her eyes are bright. more..
The Eighth Durga is "Maha Gauri." She is as white as a conch, moon and Jasmine. She is of eight years old. Her clothes and ornaments are white and clean. more..
Ninth Durga us Siddhidatri. There are eight Siddhis - Viz- Anima, Mahima, Garima, Laghima, Prapti, Prakamya, Iishitva Vashitva. Maha Shakti gives all these Siddhies. more