Newtons Color Disk Apparatus

The seven colors in Newton's optical spectrum (red, orange, yellow, green, blue, indigo and violet) may be recombined in a number of ways, including the seven-mirror device and the oscillating prism. Newton himself suggested the use of the color wheel, in which wedges of paper with the seven colors on them are pasted onto the surface of a rotating wheel. Normally a number of complete sets of colors are present. When the disk is rotated, the colors blur together and the eye, unable to respond rapidly enough, sees the colors mixed together to form white. Since the eye is more sensitive to colors in the middle of the visible spectrum, the wedges with yellow and green are often made narrower, while those for red and violet are made wider.