Change colour of background colour

It looks like you are setting the background to the ticks and all children using:

.mtphr-dnt-tick, .mtphr-dnt-tick * {
    color: #ffffff !important;
    font-family: ‘Arial’, sans-serif !important;
    font-size: 25px !important;
    background-color: #FB2405 !important;
    line-height: 28px !important;
}

But, you need to also set the background color of the tick container. It looks like your theme is already setting the background a couple times:

.scheme_default .mtphr-dnt-tick-contents {
    background-color: #ff4b64;
    color: #ffffff;
}

Which, is then overridden by the following css:

.scheme_dark .mtphr-dnt-tick-contents {
    background-color: #624BFF;
    color: #ffffff;
}

If there’s a place to add custom css to your site within the dashboard add the following:

.scheme_default .mtphr-dnt-tick-contents {
    background-color: #FB2405 !important;
}

This should force the ticker container to use your red color for the background.

You are a hero. Thank you so much for your help, that worked a treat!

Great, glad to help!