It sounds like you discovered a new way to dye wool, with stable, permanent "earth-tone" red/orange color. Way to go!

How much wool did you put on there? I find that great hunks of wool make excellent mulch, small bits are good compost. Whichever, it will eventually decompose. The red is probably from the lanolin going mouldy. Whatever made you want to wash the wool that had been on the heap anyway?

its just curiosity i guess. i just wanna know whether the wool could decompose when put dangling on top of compost. i dont know whether it is related to the lanolin, cos i suspend a piece of recycled paper on top of my compost 3 days ago and today the whole paper turns orange too. btw the wool was from a pack of band aid. the interesting thing is that the red gets darker red each day until i wash it over and over which seems like putting stop to the darkening of the wool. i am going to try a white shirt tommorrow, its just that this is a strange phenomenon and is there anybody who can explain why.

Maybe it is red purple bacteria.

it is not purple. the color more to orange. when it gets darker it turns to red black. i experience purple before. it wash off to black. my white shirt turn orange just in one day and the color wash off to lighter orange and yellow. what happens? the white shirt is cotton linen.

Purple bacteria are just only called purple. But they can be red, yellow or green. Cover clothes with blue plastic film. Color can change to blue...

do you mean to the red color will look blue under the blue plastic film? what is blue plastic film? is that presentation transparency plastic sheet but blue in color? is this bacteria dangerous? why the color wont wash off? where does the color come from? dead bacteria or secreted fluid? btw thanks for your help on this. i could feel there is something i can make out of this but i couldn't figure out what yet.

Purple bacteria are photosynthetic bacteria, that is they make photosynthesis under the light as like plants do. They use other spectrum of light than plants. They use infra-red rays. What makes them color is pigment complex which serve as acceptor of light. It tends to have color of the light spectrum which bacteria use for photosynthesis. If they use red spectrum they are red, if green they are green,etc. Different photosynthetic bacteria may have red, green and blue pigment. By mixing RGB colors any other color can be obtained. And the composition of bacteria will be the same. So, under any color they will have the same color. Plastic film serve only as a light filter. But it takes 2-3 weaks for exposure to this light.

These bacteria are not dangerous. They can live inside wool tissue and thus don't wash off.

But this is only one of possibilities.
Besides photosynthetic bacteria it can be also actinomycetes. They are dark red and not dangerous too.

Thx for the info. but my compost is in a wooden bin and completely closed by a lid, unless when its opened for turning, there's no light inside the bin. So is it actinomycetes then? But I will try covering it with blue plastic film. You seem to be very knowledgeable on this subject which leads me to ask another question, how to culture this bacteria? on agar media or any-else? And do I get the starter bacteria from the shirt or from the compost itself? Please help. I'm sure there really is something to this which I can't figure out what yet. A natural dye? or a sustainable agar planting media etc.

OK,
Photosynthetic bacteria are anaerobic, i.e. don't use oxygen. They also use infra-red rays, it's not visible spectrum of the light, it's present even in the dark. So, even bin is closed by a lid, there is infra-red light there. Photosynthetic bacteria can live in the soil down to 1 meter (the depth of infra-red light can penetrate).

Cultivation of this bacteria is made in Winogradsky column. Google "Winogradsky column" to get a lot of information. I made it at home. It looks like:

{{gwi:275200}}

Greens on the top are algae, red - purple sulfur bacteria.
Such a column can stay ad infinitum with the live there, though it is closed on top from the air.

When pieces of plastic film with different colors are stuck to the walls, then bacteria change their color respectively after pieces of plastic film are removed.

There are many other interesting properties of this bacteria. Winogradsy column can make electricity comparable with electric batery. And photosynthetic bacteria capable to live at very high temperatures, up to 1200 C. It is asumed that they were first living creatures on Earth and were living in upper layers of atmosphere when temperature there was +900 C.

They also "eat" toxins such as H2S and CH4 and make antioxidants. That's why they are used in septic systems.

But if it is emitting sulphur then I don't think its the cause. Cos the shirt still smells of geosmin after the first wash, the smell gone only after I use detergent to wash it. There doesn't seem to be any trace of sulphur smell.
And looking at the column, am I suppose to fill it with my compost and top it with water afterwards?

Wool has sulfur itself. If it decompose it release S and H2S. In small amounts but enough for bacteria.
Try compost with water, close with plastic film. Interesting to see result.

I've emailed you the tools I used. So let's say if I take the shirt out and I wanted to say darken the color what should I feed the bacteria on the shirt (in absence of the conmpost)? And if the shirt were to reach desired color how can I stop the process of the darkening/maturing (red redder) of the color? Cos the 2nd shirt I try were taken out of the box orange and by third day it gets redder.

Really, I don't know what to do...
Desifect somehow... If you want...
Good idea to take it in microbiology laboratory.

Actinomycetes are one of main inhabitants of compost.

{{gwi:275201}}

Here is a link that might be useful: Actinomycetes

Wow now I get it, the color of the compost comes from this bacteria as well. Which, brings me to most important question. How do I get to pure culture of actinomycetes? Using winogradsky column is obviusly out since its mend to be variety of microbe. Where I only want the actinomycetes. Any knowledge?