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", "It will be Summer--Eventually" and "Me, change! Me, alter!"
The use of the color purple is based upon the meaning of the color. The color purple is known to represent good judgement, spiritual fulfillment, and peace of mind.
In regards to the poem "Again- his voice is at the door", the color purple appears in the following stanza:
I'd give—to live that hour—again—
The purple—in my Vein—
But He must count the drops—himself—
My price for every stain!
What the speaker is referring to, in this poem, is the wish to have blood running through her veins again. It is apparent, through the previous movement of the poem, that the speaker has passed on. In regards to this, she wishes that she may be able to spend time with the one who has come to seek her out. Instead of continuing life, the speaker has come upon Heaven. The man, whose voice is at the door, accompanies her only so far. She must go on alone from the departure point. This is shown in the following lines:
Alone—if Angels are "alone"—
First time they try the sky!
Alone—if those "veiled faces"—be—
We cannot count—on High!
Therefore, the color purple, in the poem, represents spiritual fulfillment.