Unlike Newton, Goethe believed that light was homogenous, that is all of a piece, not split. As a Romantic, Goethe accused the rationalist Newton of destroying the harmonious nature of light. He felt Newton was disregarding the human, emotional aspect of observation, reducing everything to a mathematical formula. Of course, as a scientist, this is exactly what Newton was doing. It was good scientific practice.
But Goethe could not accept Newton’s concept that the eye was a passive recipient of light, believing that the eye generated its own internal lighting and colour effects. He maintained that the spots of colour that appeared to a person after directly staring at the sun were proof of this. We can see that Goethe's theory was based on the Romantic ideal of the harmony and power of nature resulting in the emotional impact of light on the eye of the individual.
Nowadays we can accept that Newton's scientific theory and Goethe's Romantic philosophical ideal both have their place.