Comfort Bias is different from other ways a player can alter their comfort. Most sources of comfort gain or loss are short-term, and removal of the positive or negative influence will shortly be followed by a rise or fall in that player's comfort back to its base value of 50%.
Comfort Bias stays with a player for a long period of time, allowing a player to, in the absence of other sources of comfort gain or loss, increase or decrease their comfort. It has a half-life of 30 minutes, so it sticks around quite a long time.
There are only two ways currently to influence comfort bias, one positive and the other negative. The only way currently to improve comfort bias is to consume comfort granting flowers. The only way to reduce comfort bias currently is to consume fish as a non piscivorous creature.
Altering a player's comfort bias is a method a player can, with enough effort, significantly increase their comfort rating regardless of presence or absence of other friendly players or a strong pack or herd.
It is highly likely that a player who appears bright green or blue on the scoreboard has a very high comfort bias, bolstered by consumption of many flowers that increase comfort bias.