The photo was taken April 1, 1995.
According to the Hubble Site:
The color image is constructed from three separate images taken in the light of emission from different types of atoms. Red shows emission from singly-ionized sulfur atoms. Green shows emission from hydrogen. Blue shows light emitted by doubly- ionized oxygen atoms.
The beautiful Pillars of Creation image has been repeatedly compared to Thomas Moran's painting Cliffs of the Upper Colorado River, Wyoming Territory (1882)