What is the act of using different colors to distinguish motifs or pattern in a poem?

The act of using different colors to distinguish motifs or patterns in a poem is not a standard literary technique. There are no established terms or conventions for this.

It's possible you're thinking of a technique where:

* Imagery: The poem utilizes vivid descriptions that evoke strong visual imagery, perhaps using color to emphasize certain elements. This is a common technique for creating a particular mood or atmosphere.

* Symbolism: Colors are used to represent abstract ideas or concepts. This is often done through metaphors or similes. For example, "blue" often symbolizes sadness, while "red" can symbolize anger or passion.

* Themes: The poem might explore different themes through the use of color. For example, a poem about love could use red and white to represent passion and purity.

However, the idea of "distinguishing motifs or patterns" through color directly within the text of a poem is not a conventional approach.

Perhaps you can provide an example of what you have in mind? That might help clarify what you are referring to.