how to link legend icon color automatically to data color?

Question

Background:

1. We'd to compare year-to-date(YTD) data VS forecast(CF). target achieved -> green color, otherwise Red.
2. we use formula to make bar color update based on above logic.

Problem:

1. legend color (circled in blue in above pic) can not be automatically updated based on bar color. or it doesn't know how because there're 2 colors

Question: How can i make legend color and YTD color sync? is there any better visual to be applied?

Many thanks in advance!

BR

Hanny