Hi Joy,
another explanation is for dark/night modus switch, the dropdownmenus by ES change colors too.
Currently, it is developed to shown that way and it will not change when you switch to dark/white menu
Perhaps it would be best if you can submit a feature request regarding this issues by creating a new ticket on the forums and set it to "Feature Request" so that everyone else could vote for it. We will prioritize this feature during the development process for the next major version of Charm if there are more people request on this.
Thanks for your understanding.