Good evening Cindy and welcome back!
Thank you for reaching out to us.
I would love to help you with this topic.
I have not been able to change all the colors around TEC.
I’ve gone into Appearances and TEC and replaced all sections that were green with white. It did not work out
According to your system information, you are using Avada.
As it turns out, this theme bypasses the Customizer found under Appearance > TEC and replaces it with the one found under Avada > Theme options > the Events Calendar
Let me know if that helps.
Have a great day!
Geoff B.