Hello @heidi
The free version of the theme restricts the options of color customization of the sections that you have highlighted unlike the pro version of the theme.
As long as we would love to help you, can you please specify which color do you prefer to change the titles to so that we can provide you with a custom CSS along with your site URL ?
Also, You can check the pro version of the theme and features provided by it in the given link : https://wenthemes.com/item/wordpress-themes/wen-corporate-pro/
Hope to hear from you soon,
Best Regards!!