Why is mold that ugly turquoise color?

There are a lot of kinds of mold. It’s not all turquoise. Most of the mold I see is white or black.

The pink mold on the sour cream I was about to put on my fajitas last night was really cool. And I had blue mold on some cream cheese once.

I bet if you went to most random bachelor’s refrigerators you can find a whole spectrum of mold colors.

I asked a similar question about larger fungi a while back; it was lost in the great purge, but it’s archived here

There’s not necessarily any reason why a fungus would be green or black or whatever. Chemicals have colors, and fungi make different chemicals. A particular fungus may make a particular pigment for purposes that have nothing whatsoever to do with the pigments color.

I have discovered a new art-form unintentionally - Bonsai mould!

I made this discovery after finding an old, opened tin of bamboo shoots at the back of the fridge. The whole surface area was covered by a small, perfectly circular forest of multi-coloured mould. There were many different sizes of growth distributed so as to create the impression of a serene natural microcosm.


There’s no evolutionary pressure from us on it to have a color that we don’t like, so the reason must be on our side. Not the reason for it having color, but the reason for us thinking it’s ugly. People thinking “Oooh, yummy, pretty green bread!” won’t live long. We think mold is looking ugly because we don’t like it because evolution has taught us to avoid it.

And mold has learned to be toxic and ugly to avoid being killed or eaten, by whom-or-whatever. Maybe some mold has color because something ate all the non-toxic, non-colored mold. Or some species wiped out all but the colored mold because something else taught it to avoid those colors or chemicals. Or color is useful to the mold and it’s just us having learned.

It’s usually a mutual or even multilateral relation. Without pressure from the environment or from other organisms there wouldn’t be a direction of mutations. Of course there are pretty but poisonous (to us) red berries and perfectly harmless blue molds. Eventually one of the involved species will change or learn or die. It’s evolution at work, and there isn’t always a definite reason for something being like it is.

Er, Mangetout, but, … huh? Your thread: Pigmentation in fungi (fruiting bodies)

papertiger, You’re not the first one. It’s bacterias, not fungi, but people already grow them to create pictures: