Haven't been able to create a tree map - size and color can be used to represent 2 dimensions.
Might want to represent the absolute $ value by the size and the YoY% by the color. Cannot do this currently in the cards.
Thank you for submitting this @njain. I am assigning to our product manager @Gavatar to review and comment.
Thanks for the suggestion. We are releasing a new color rules feature this summer which might accomplish what you are trying to build.