I mean, 2 weeks after being used, not 2 weeks after being made :D
My photo technique is not good. And I didn't take the photo at same time of the day. The first one was taken in day time, and 2nd taken at night. But at same location for both, and both times with my big, bright studio light on. I tried to adjust whole photo of the second one to make it have about same color level for the wall and table, and therefore the color contrast of the pot is more real. The top one is before use, and the bottom one is 2 weeks after being used. The photo doesn't express it very well. But I can tell the changes of this pot. Before use, it had some orange-red hint (a little red brick color). And not it's turning to darker color with a bit shine on the surface. I use it for "greener" oolongs, include Anxi Tie Guan Yin and green roast Taiwan oolongs.
It's Qing Shui Ni Tiao Sha (清水泥調砂). This is a (relatively) inexpensive teapot and is not perfect. But I like it very much and soon feel personal attachment to it :D I don't know much about zisha clay and techniques of yixing zisha. But this one, I can tell it's more seriously made than another one I bought at the same price level by another author. I believe all these authors of mid-low price range teapot can make better, a bit more expensive ones. It all depends on how seriously they treat each pot. Even for mid-low price range teapot, some authors have strict bottom line in terms of quality, while some others rush to finish lots of pots without good enough quality control. Even as an inexperienced user, by using the pots and holding them in hands frequently, eventually I can see the quality differences between two pots.
At this stage I don't plan to buy any expensive teapots. Although half-handmade teapots like this one can hardly be considered art work, I give my respect to widely-affordable-level teapot authors who strive to create work of quality.
18 hours ago