You can change Testimonials speed, font color and background color by going to Avada > Theme Options > Fusion Builder Elements > Testimonials Element. Read the description and enter your desired value.
You can change the Testimonial font size with the following custom CSS:
Copy to Clipboard.review blockquote q {
font-size: 18px !important;
} 1.review blockquote q {2font-size: 18px !important;3}For more details on using custom CSS in Avada, please see our guide here.
How To Change Testimonial Speed, Fonts, Background
How To Change Testimonial Speed, Fonts, Background