Future Calendar Issue

i’m using the Future Calendar Plugin (https://anthologyoi.com/wordpress/plugins/future-posts-calendar-plugin.html) on the left side of this site: https://www.goldcoastchamber.com/.

But for some reason, the second future post is always highlighted in a different shade of blue (background-color: rgb(122, 255, 222);) than all the rest (background-color: rgb(40, 110, 160);).

i’ve searched for these two code snippets in my entire site but can’t find them anywhere. any idea where to find them or how to fix?

please advise. thanks.