Understanding Of Colour Changes

I'm light of my silly call recently :) (I have no problems looking silly to learn)
I was thinking maybe we could post a couple colour changes and break them down a little.
It was my understanding that all colour changes where damaged (with the exception of a few)
I enjoy looking at some of them, not interested in any value talk
maybe some explanation for anybody's changlings can be posted here?
Maybe?
I'm sure people have some :)
Seeing I failed this morning on a Norway stamp :)
I'll start there but please add if you can!

Nice example.

For a long time Great Britain SG213 was thought to have had a blue cousin. It is now known that is a colour changeling and it was only printed in (blue-)green. SG deleted its earlier listing a few decades ago.

Have you tried to search for "color change" (yup American spelling)? They pop up quite often in threads.
Some have comments on which colours tend to fade quicker than others, causing the colour to change.

And yes, it is a type of damage.

Do lots of searching:) but I'm not really all that good at it!
I read lots, but I learn best usually seeing and talking threw things :)
Maybe there's a few others that have questions for one or two they have, maybe?
I find them fun to look at! some I think look better damaged :)

There are dozens of threads about colour changes on this forum with images.

I think it was Don who gave an explanation on what colours change easier than others and what is the result.

More here https://stampsmarter.org/learning/A...gelings.html
Don

One of the first articles I read :)
Great read, very informative
And makes perfect sense!
I just want to see and talk about some of the odd stuff people may have.
Not digging for value just fun and though :)
Silly stuff I guess...
(that may stay for the wonder and beauty they bring to the pages)

I'll give an example.
The middle stamp is damaged (chemical or environmental) I'm good with the explanation I got!
But I placed it aside intentionally to add to the page
Shows what the ink is capable of doing and adds some fun!

The British Penny red was susceptible to a colour change when exposed to a sulphurous atmosphere, Seeing as sulphur was in house gas and also atmospheric pollution. a few penny reds can look almost Black, so I have in my collection a stamp an apparent rarity a penny black with perforations! some stamps have fugitive ink, ie they fade easily, usually when you ar soaking them off the paper. Plain old dirt can also lead to changes in color.

All sorts of things can happen!
I would like to see your penny black would you post a picture?