changing colors

so i see that through the ui i can change the colors. the color picker updates the #hex value in the text field. however it does not work in reverse. if i enter the hex value into the text area, it does not update the color in the box next to the parameter, and won’t save my color selection. i don’t want to use the color picker because i have a very specific color i am working with. what gives?

https://www.ads-software.com/plugins/all-in-one-event-calendar/