Green (Qing si) was Lu Yu's favorite color for tea cups and bowls. I already explained why in an article some 2 years ago. In the meantime, I have added different shapes and sizes of celadon cups to my selection. Here, you can see them all together on one picture:
We can separate them in 2 categories. On the left, the big cups (around 6 cl) and on the right 2 smaller sizes (around 3 cl):
On this picture, I have repeated the tea color experiment. I have used the top grade 'lily flower' Baozhong for this purpose, a very lightly oxidized Oolong.
Again, we can see that the tea will look light yellow in the white cup (top right). In the celadon cups, on the other hand, the tea looks like a fresh green. Size and shape of each cup will also impact the brightness of the tea. The shallow cup make the tea appear more light.
These celadon cups also provide for a different tea experience because they are rather heavy (50 gr to 80 gr) and yet there glazing is extremely smooth. Usually, we strive to drink from a very thin cup in order to forget about the cup. With these cups, though, as you bring it to your mouth, their weight and smooth touch is almost like a kiss!
This kind of feeling works best with sweet teas with a lot of body, like roasted Oolongs or cooked/old puerh, I find.
Interestingly, the color of cooked puerh is also impacted by the celadon. Here, the white cup is in the middle and the tea looks more red. In the celadon cups, the tea has a brownish appearance. And with the shallow (triangular shape) cups (see below) the tea goes through a greater color gradiation. The large rim is very different from the darker color in the center of the cup. This makes the tea appear more mysterious as its color changes depending where you look in the cup.