I have always been amazed at the difference in color that arises when you steep a deep-steamed tea (fukamushicha) for the first time at low water temperature and a second time at a higher temperature.
I posted such a comparison recently on the tea subreddit here ("What a difference temperature makes for Japanese green tea!") and the community pointed out that this shouldn't be used for comparison because there were so many different variables.
The tea used was Kuma Tea Gardens' Sencha Saemidori, and I decided to try a more accurate comparison...with only the water temperature as a variable. Here is what I got.
1st steeping - Tea: 3g. Time: 2 min. Water amount: 100 ml. Water temperature: 55C and 95C.
2nd steeping - Time: 20 sec. Water amount: 100 ml. Water temperature: 95C.
Take a look at the results. Low temperature 1st steeping is on the left, high temperature on the right. They aren't quite as dramatic, especially without Photoshop enhancement. What's particularly interesting is that in the 2nd steeping, the tea that used a low temperature 1st steeping is slightly more green than the one that used the high temperature.