Small follow up diff to address comments in D8310.
In this diff I removed all the instances of the panel color family and the emoji keyboard specific colors and committed to using the modal color family. Please note I tried really hard to reuse existing color variables and to not introduce any new variables for this; however, this did lead me to using some variables that didn't "fit" the proper description even though it was the best fitting color. I will highlight this using inline comments and offer an alternate solution if we think the current variable name is not fitting well.