Between far away and close by: green 20%, grey 20%, blue 12%, …
Heller (1989)

Depth: blue 54%, grey 13%, white 10%, …
Heller E. (1989)

Distance: blue 54%, gray 13%, white 10%, …
Heller E. (1989)

We connect distances with colours because colours change through distance. Red is only bright when it is close. The further away, the more bluish it becomes.
Heller E. (1989)

All countries: many different hues and shades. Germany: light colours, whereas dominant is light blue. Japan and Russia: dark colours.
Jung et al. (2018)