Here is a super cool chameleon Diamond.
The color change goes like this: if you put the diamond in the dark for eight hours, when you first take it out you will notice quite a bit of green. As it warms and reacts to daylight, you will see more and more yellow - although the green never goes away.
If you heat the diamond up, it will likely show an orange yellow. If you do that, be careful not to burn yourself, (as I've done)
Lovely Pear in terms of shape and light performance and sparkle.
Eye clean SI2 - the depth of color helps in this regard.