These sidebar themes for Slack were created with the USF Colors in mind. To use them, on desktop, go to Prefences -> Sidebar and then paste the values into the Custom Theme box. Alternatively, you should be able to paste them into any channel and a button to apply the theme will appear.
#006747,#009374,#cfc493,#444444,#009374,#f6f6f6,#9ccb3b,#db6668
#f9f9f9,#d9d9d9,#006747,#ffffff,#d9d9d9,#383838,#9ccb3b,#c75b5d
#cfc493,#aba27b,#006747,#ffffff,#eeeeee,#222222,#006747,#c75b5d