Font size and color on paralax

You can try changing the font size and colors by adding the following CSS code in the Custom CSS option of your theme on the below path.

Admin Area -> Appearance -> Customize -> Shapely Options -> Other

.shapely_home_parallax p.mb32 {
    font-size: 16px;
    color: #000;
}
#page .shapely_home_parallax h1 {
    color: #000;
    font-size: 60px;
}
a.btn.btn-lg.btn-white {
    color: #000;
    border-color: #000;
}

Please change the font size and color value in the above code to whatever you want to use by referring the following pages.

http://www.w3schools.com/html/html_colorvalues.asp
http://www.w3schools.com/tags/ref_colorpicker.asp

if we can get a text input form (or the mailchimp for WP this is forms code [mc4wp_form id=”4″]) plugin on the first paralax widget (the one with the runner picture and readmore and signup buttons).

You can achieve this by using custom plugin solution shared in the following topic. Please add that shortcode in the content section of widget.

https://colorlibsupport.com/t/cusomizing-parallax-widget/

This plugin deletes the existing parallax widget and adds new parallax widget having extra functionality so please read the new parallax widget in the Homepage widget area and configure it.