All things in creation can be used for good or evil. And the Devil is clever, in an evil and pitiful sort of way. He inspired some fool to hijack a Biblical covenant into a dysphoric flag in the likeness of a rainbow. This evil is a perfect sign of the entropy of creation (see here). We are not fooled.
And God said, “This is the sign of the covenant I am making between me and you and every living creature with you, a covenant for all future generations: I have placed my bow in the clouds, and it will be a sign of the covenant between me and the earth. Whenever I form clouds over the earth and the bow appears in the clouds, I will remember my covenant between me and you and all the living creatures: water will never again become a flood to destroy every creature. The bow will be in the clouds, and I will look at it and remember the permanent covenant between God and all the living creatures on earth.” God said to Noah, “This is the sign of the covenant that I have established between me and every creature on earth.” Genesis 9:12-17 CSB