The Camouflage Color Changing Chameleon Challenge

lambda l:[sum(r)+4>>3for r in zip(*l)]

Rounds the average (towards the nearest integer, with halves rounding up) by adding 4 to the sum, then floor-dividing by 8 via the bit-shift >>3.

MATL, 8 4 bytes

YmYo

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4 bytes saved thanks to beaker!

Explanation:

Ym          "Get the average of each column
  Yo        "And round up

S+4:8

Test suite. (Slightly modified so as to verify all testcases at once.)

S+4:8
S      sum (vectorized)
 +4    add 4
   :8  floor division by 8