The colour yellow in relation to hunger caused in humans in mostly temperate climates, as explained by Graham

I have no idea if this is an original idea, and even if it's not I came up with it independently because I never read studies unless they're about penguins, or my professor made me.

So I was driving through Fish Creek (I was actually walking) and I noticed that, shockingly, the trees were red and yellow. This is caused by the dip in temperatures we have in autumn as the tree's chloroplasts stop producing chlorophyll and instead make something that ends in "ase". Or some jazz. The important fact is this:

It gets colder

Trees create warm colors.

Trees are generally green when not yellow, red, or aflame.

Now with those three key facts, I think we're about to explain something. But we're missing one more fact about the human brain: the colors red, yellow and orange have the psychological effect of appetite stimulation, uneasiness, restlessness and increased blood-flow. The color green, however, IS the most calming color the human psyche, and also the color we can distinguish the most shades of. Is anyone else thinking what I'm thinking?

The reason those colors make us feel that way is because it's getting colder. We need to stock up on fat and all that stuff, we need to migrate to warmer areas. Without even realizing it, I think people living near deciduous trees are subconsciously conditioned to stock up on fat and get the fuck out of there the moment the fireworks start. We can see the most shades of green because as soon as shit gets green, we sit down, build a hut, and relax. It's that simple. We're in tune with natures thermometer. Wow! What a hypothesis!

BUT WAIT!

What about Africans? What about people in insanely warm climates? I wonder if this interaction could even take place with people not originally from a northern forested area. Theoretically, this cannot be a base instinct from our monkey ancestry, because we originated in east Africa, an area not really known for it's brisk autumns and chilly winters. So I postulate that people from climates that do not experience seasons the way we do are not affected by color/food response, and just wing it.

WHICH MEANS THIS:

McDonalds scheme of painting the insides of its buildings red and yellow to make people uneasy and hungry so they'll eat and leaf, haha, will probably only work on white folks from deciduous-ly forested areas. Discuss.