Many of Emily Dickinson's poems include a reference to the color purple. A few of the poems are "There is a flower that bees prefer", "Wait Till the Majesty of Death", and "We like March", and "It will be Summer--Eventually." The poem "Me, change! Me, alter!"
The use of the color purple is based upon the meaning of the color. The color purple
is the color of good judgment. It is the color of people seeking spiritual fulfillment. It is said if you surround yourself with purple you will have peace of mind. Purple is a good color to use in meditation.
Therefore, the use of purple in the poem refers to the fact that the speaker is altering them self. By altering, or changing, the speaker is able to end their day on a superior note:
At Day's superior close!
It takes good judgement to recognize the fact that one needs to change them self.
Another interpretation of the use of the color purple is the tie to spring:
Purple has a special, almost sacred place in nature: lavender, orchid, lilac, and violet flowers are often delicate and considered precious.
Based upon this understanding of the use of the color purple, purple could reflect images of springtime given flowers are known to bloom during this season. This being said, with spring comes new life--new flowers and new life. The poem's speaker is talking about creating a new life for them self- something similar in spring. This can be interpreted from the line:
A Smaller Purple grows.
The small purple can refer to a small purple flower which accompanies spring.