Yes, there are many other elements linked to the sidebar colour. ??
In this post, I helped another person change the colour of the decorative double lines in the sidebar, so have a look:
https://www.ads-software.com/support/topic/how-to-edit-lines-above-site-title?replies=5#post-5327923
For the “Continue Reading” button, I used Firebug to select the element and find its class:
.more-link {
background-color: #xxxxxx;
}
Learning how to target your site’s CSS will help you make certain design changes. Here are some very helpful posts that will help you customize your site with CSS:
https://dailypost.wordpress.com/2013/07/25/css-selectors/
https://dailypost.wordpress.com/2013/06/21/css-intro/
https://dailypost.wordpress.com/2013/08/29/css-matched-rule-pane/
You may want to look through the stylesheet to find all instances of the original sidebar colour, so you can be sure to find and change them all:
https://blog.copyjoint.com/wp-content/themes/writr/style.css
Finally, just a big heads-up that since you’ve opted to edit the theme’s stylesheet directly as opposed to using one of the recommended methods above, the next time you update the theme, all your changes will be overwritten. Please be careful. ??