Because metals have free electrons, so they have almost continuous energy states going up and down different energy levels and repeating themselves, most metals are silver-white, right? But why do gold, copper, and cesium have special colors? I wanted to know more about this, so I studied the concept of obituary contraction. I know up to the fact that by orbital contraction, s orbtal is contracted by applying a relativity effect. To conclude, I wonder why gold and copper cesium have special colors. I want you to explain in detail and in detail. I've turned the translator. It may not match the terms you use. Please consider this.