A child theme does not affect option values.
The Appearance -> Theme Options is generated and controlled by the parent theme which is Evolve Plus Theme.
I will not go into details in explaining how WordPress or Child Theme works.
If you need help on changing color of button.
Please post your website URL showing the button and tell me the color hex code, I will provide you with css code to add in Appearance -> Theme Options
If you want to continue with sharing programming knowledge, I will get my employer to share with you.