I often overthink how to visualize them: 2d disclike or 3d balls? spinning clockwise or not spinning? large or small? And I have a very hard time visualizing the indigo color too. Do these details matter?
Empower with another sense.
Grab a frisbie for example, hold it in your hands, look at it, "study" it, turn it on each side, spin it, throw it, define it as a disc, draw it on paper.
Do a similar cognitive recognition exercise with ping-pong balls or tennis balls.
Some individuals don't have a "trigger for that element" in their library but can be created through experience.
About indigo color.... I will not dive into the subject but colors are nothing else but light on various wavelengths (indigo is 420–450 nm) and frequencies (~714–670 THz for indigo) therefore you don't necessarily have difficulties with the color indigo but with the frequency manifested as color.
Before anything else, avoid looking into the sunlight (some people do sungazing) and do this (anyone can try the following).
Indigo is representative to a relatively high frequency but our visual receivers (eyes) are developed to detect a specific (narrow,limited) wavelength from the entire spectrum we can detect, perceive and define only 0.000000000037% from the entire spectrum so we are kind of blind.
But try this: no matter if it is day or night, close and open your eye as fast as you can and kind of try to perceive what you see imprinted on your retina.
Maybe the conscious mind has not processed some of the images captured by the eye but the unconscious mind surely did...
Sometimes one can see shapes, geometric ones, or poly geometric areas... sometimes just "static" ...
It is fun, easy to do, not dangerous and maybe you can discover some information your brain has failed to process in a normal way.