olemus
pildi üldine visuaaltoon
= the general visual tone of an image

(4a) üldine heledustase (light/dark)
high key = hele
https://duckduckgo.com/?q=high+key&t=h_&iax=images&ia=images
low key = tume
https://duckduckgo.com/?q=low+key&t=h_&iax=images&ia=images

(4b) valdav värvitoon (the prevailing color)
https://duckduckgo.com/?q=blue+key+painting&t=h_&iar=images&iax=images&ia=images