“使呈彩虹状”可以翻译为 “to create a rainbow-like effect” 或 “to make it appear in a rainbow pattern” 等,具体表达可根据语境调整。例如:
The artist used special pigments to create a rainbow-like effect on the canvas.(艺术家使用特殊颜料在画布上创造出了彩虹状的效果。)
They dyed the fabric in such a way that it appeared in a beautiful rainbow pattern.(他们以这样的方式给布料染色,使其呈现出美丽的彩虹状图案。)