Chameleon rose

From Memory Alpha, the free Star Trek reference.

A chameleon rose is a flower that changes color with the mood of its owner.

In 2364, Wyatt Miller gave Deanna Troi a chameleon rose as a gift.

The rose had golden leaves and a golden stem. It was blue when Wyatt held it and turned red, then white when Deanna held it. It later turned purple while still in Deanna's hands. (TNG: "Haven")

Though Deanna's mood changed once her mother arrived, the rose remained white.