3wave. Trichromatic theory predicts that anyone with normal color vision can match the color of a single wavelength by mixing varied intensities of three other wavelengths. You can simulate that experiment here. Adjust the three sliders to match the center circle to the color of its surroundings. People with color blindness can match the target wavelength by adjusting only two wavelengths. This shows that they have dichromatic vision. To simulate that test, select one of the types of color blindness in the Vision menu.