I would like to be able to control the "secondary colours" (pink) of SPO sites so that they are the same as the branding along the top (dark blue).
Anyone know if/ how this is possible please?
Primary and Secondary colours
You will have to update the site theme. In this article is described what you need to do to update or add a site theme:
It involves at a minimum some powershell scripting.
April 04, 2018