Red dye - Green dye when frozen, same end colour!

Factual Questions
1

In high school, which was a long time ago, I did a chemistry experiment along with the rest of my class in which we manufacture a mordant using stock chemicals. This turned either orange or red, and was supposed to turn a sample piece of cloth either red or orange (the opposite of the above color, but I can’t remember whether the cloth or the dye itself was red!)

However, my lab partner and I were not done by the end of the period so we put the results in the freezer to commence next time. When we opened the freezer to take out our half-completed experiment we found the dye had turned bright green!

And this is the weird part, when we were done the dye was still green - but it still turned the cloth the expected red (orange) color! How weird is that?

Is there a common chemistry dye-producing experiment that will change from red to green in a freezer but keep its original color-forming capabilities?

2

??
It’s obvious you don’t dye your hair!
Many of those new-fangled hair dyes aren’t the color you dye your hair. I believe it’s the oxidization of the dye on the dye substrate that gives you the final color. But then again, I only took art classes, not chemistry…

3

I know that there are chemicals that can do this. I was just surprised that one of them could change from red to green permanently when frozen and remain functional, and I was also wondering if anyone knew what I could have been experimenting with.