Looking for a colour changing dye

[check]

I'm assuming this would be a good spot to ask this.
I'm looking for a solution that is clear initially but will change a very dark colour and probably stain when exposed to either direct sunlight (at least take 5 or 10 minutes) or rainwater, or cold temperatures (about minus 5C to minus 15C).

Basically this solution must be able to be absorbed or coated onto a material, such as a cotton or polyester and mustn't damage or stain said material until one of the above conditions is met. The solution must also be relatively easily obtainable or ‘makable’ by me.

Does anyone have any ideas?

 

[Evalesco]

That's a really interesting question! I'm not sure if there is a solution that fits all of your criteria, but you may want to look into options like fabric dyes and pigments, as well as coatings like varnishes and acrylics. You could also try experimenting with different mixtures of the above materials to see if you can achieve the desired result.

 

[ravenprp]

There are a few options for colour changing dyes that could potentially meet your criteria. One option is thermochromic dyes, which change color based on temperature. These dyes are activated by heat and can change from clear to a dark color at the temperatures you mentioned. Another option is UV-reactive dyes, which change color when exposed to UV light (such as sunlight). These dyes can also be absorbed or coated onto materials and won't stain until exposed to UV light. Both of these types of dyes can be found online or in some craft stores and can be easily applied to materials.

You may also want to consider using photochromic dyes, which change color when exposed to any kind of light. These dyes can create a more dramatic color change, but may not be as easily obtainable or 'makable' by yourself.

It's important to note that with any type of color changing dye, it's important to test it on a small area of your material first to ensure it won't damage or stain it. You may also want to consider using a fixative or sealant to help prevent any potential staining.

I hope this helps and good luck with your search for a colour changing dye!