Hi there!

Thanks for your query.

Actually, you can change the colors by using custom CSS. https://prnt.sc/26fa6g7

You need to enter your codes within the custom CSS field of the Template. Here are some example codes for you:

.sp-poll-result .progress-bar.progress-bar-primary {
background-color: red;
}
.sp-poll-result .progress-bar.progress-bar-info {
background-color: green;
}
.sp-poll-result .progress-bar.progress-bar-default {
    background-color: blue;
}

Note: Path towards custom CSS: Extensions>Templates>Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.

The following blog may help you in this case: https://www.joomshaper.com/blog/which-line-of-css-i-have-to-edit-code-inspector-in-action

Best Regards