The word "polychromous" refers to something that has many different colors. If you are looking for synonyms to replace this word, you could consider using the term "multicolored" instead, as it has a similar meaning. Other options might include using the terms "variegated," "varied," or "diverse." These words would all indicate that something has a range or combination of colors or hues. You could also consider using words like "colorful," "rainbow-colored," or "prismatic" to describe something that is polychromous in nature. Choosing the right synonym can help you convey a specific tone or meaning within your writing.