Am I the only one that didn't know that leaves do not turn color?

[clydefrand]

Ah ha - the leaves were already that color but as they grew, chlorephyll which is green, cover the color until
fall, then the plants use that chlorephyl up, so the original color shows thru.

[A HERETIC I AM]

1. Silliness with semantics. n/t

[bigwillq]

2. They change color, dammit.

Don't ruin one of my favorite things about Autumn.

[TlalocW]

3. You're all wrong. WRONG!

TlalocW

[Igel]

4. They change color.

However, they do not add color. They mostly just subtract color. Some of the pigments were there all along, but as the chlorophyll is destroyed by light it's simply not replaced. Note that there are even different colors of chlorophyll--not all chlorophyll is green. Some is red. I think they found purple, too.

In some cases the leaves do produce new pigments (but these aren't produced for color; they're by products that are also pigments).

The net effect is that leaves change color.

It's the same with old color photographs where they've "changed color." Some dyes are more easily destroyed by higher energy light. Once destroyed, the remaining dyes produce the visible color. Dyes in cloth can also be destroyed, and since most "colors" aren't produced by single compounds what's left looks different.

Color is what's perceived based upon the light that's reflected.

Note that there are colors that are not in the spectrum. There is no real corresponding wavelength, no single pigment that can produce them. Pink, for example. Or brown.

It's also possible to have two patches of different colors which, when you cross your eyes so that those colors overlap, produce colors that cannot be printed. They exist only in the way the brain processes the information coming from two eyes providing competing and contrasting signals.

Color is perception. Color terms and how we group them are often cultural, but color itself is pretty much physiological. Some languages have sharply reduced color term inventories. More exotic colors are less often labelled--"orange" and "brown" in English are, I think I've read, post-Shakespeare. Let's not even worry about taupe and teal. To this day "mauve" is ambiguous.

[kiva]

9. Thanks for the explanation.

Good info

[KT2000]

12. thanks for this

I have been learning about the eye lately and the fact that color perception varies among individuals. I used to do costuming for plays and there were often comments that I used colors that were unusual but apt. For me the colors were the priority but now I am wondering if color perception is different than the majority or if the comments were from people who may have seen thing differently than I did.
Guess it doesn't matter now but it is a mystery to me.

[NutmegYankee]

5. That's not entirely true.

Some of the color compounds get produced after the chlorophyll is used up. Anthocyanin, the red that blazes Sugar Maples in the North East, is formed in the fall.

[senseandsensibility]

6. I just remember reading that the beautiful colors meant the

leaves were dying, which should have been obvious. Still, it was kind of a bummer to see it expressed so bluntly.

[KittyWampus]

7. your thread ends up being very interesting and educational. Thanks

especially to all the DU'ers who chimed in .

[Tipperary]

8. Well, they sure are pretty

I love fall.

[JustABozoOnThisBus]

10. But they all end up in a brown pile after I've raked them into the street

Must be some kind of leafy entropy going on.

[Shandris]

11. Wow. No, you weren't the only one. I've literally never heard that.

That's amazing, too.

DU. Your one-stop shop for all things political and...horticultural. Because it has 'culture' in it, natch!