Color out of Space.

The Color Out of Space (or "The Color", "That Thing" or "The Damned Rock") is a parasitic entity that travels from planet to planet, manifesting as a shimmering, indescribable color that is not in the visible spectrum of light. It will land as a comet, and find some dark, damp place to hide, as being in contact with light will cause it to slowly vanish into the air, leaving no trace whatsoever. 

The color was said to have "poisoned" the soil around where it had landed. It appeared to have "infected" the local plant life and the results were great discolorations in the flowers, grass, and trees. Along with the discoloration came the ruining of fruit and vegetables grown along with the abnormal behavior of the plants during the night. The flowers would glow in the darkness and the trees seemed to reach out to the sky and move without the wind.