Poem to the Book thief

How does this poem have a thematic connection to one of many themes of the book theif:colors? Please provide enough evidence . Thank you !

I am the birth of the forest That wants to sky up from the earth. You are the sunny herald Announcing that my thought is heard. Whence your going and coming I know, from my lucid words, Oh, fiery-flodding joy, Oh, rain of colors and flowers. I lie in the grassy damp, Entwined in the thought of your light. I feel on my body a river Blending dream and wine. Your beauty words my palate. Your fire kindles me like silk. I beg you: enliven me, cut me With streams, with colors and flowers. You, like a starbody pure, Perceive the speech of my spirit That whispers trusting to you, All my blood you release From its embalmed muteness. I do not feel how I soar Upward to you from my rest, Oh, rain of colors and flowers. You cloak me in your cape, You purify my body with your grace. Forests glimmer gold-green, Festooned with light and mystery. I feel: You perceived my prayer, Gave it flesh of vision, in such hours: Now I forest up in the air, Rained in with colors and flowers.

(Keep in mind that each line represents a color)