Colour suppression is the experience of colours becoming darker and less distinguishable from one another.   During this experience, reds may seem “less red”, greens may seem “less green”, and all colours will likely appear greyer and less saturated than they comparatively would be during everyday sober living. At higher levels, this effect can result in the external environment appearing to be black and white, monochrome, and completely devoid of colour.
Colour suppression is often accompanied by other coinciding effects such as acuity suppression and double vision. It is most commonly induced under the influence of heavy dosages of antipsychotic  compounds, such as quetiapine, haloperidol, and risperidone.
- Color Blindness (AllaboutVision) | https://www.allaboutvision.com/conditions/colordeficiency.htm
- Colour vision deficiency (colour blindness) | https://www.nhs.uk/conditions/colour-vision-deficiency/
- Richa, S., & Yazbek, J. C. (2010). Ocular adverse effects of common psychotropic agents. CNS drugs, 24(6), 501-526. | https://doi.org/10.2165/11533180-000000000-00000