Hi Peter,
Thank you for reaching out and thanks for using BoldGrid Evolv with Post and Page Builder for WordPress!
If you’re attempting to change the colors of your Event Calendar with the Post and Page Builder color controls the most likely reason for this not functioning properly is because the “Events Calendar” plugin is a third party plugin and has it’s own set of color controls.
One sure way to adjust the colors would be to select the Events Calendar elements using CSS and use the Custom CSS/JS section of your WordPress customizer to make your changes directly.
I hope this helps. Please reach back out if you have any other questions for us.