The correct answer to this open question is the following.
Although the question does not include options, we can say the following.
An undesirable effect caused by a defect, such as color or the twisting of an image by the lens of a telescope describes the word chromatic aberration.
This phenomenon of a telescope lens is also known as Chromatic distortion. It is the result of the dispersion of the velocity of the wave and its frequency. If the wavelength increases, then if makes the materials of the reflective index to decrease, provoking the distortion of the image or the color of the image.
