Thanks for reporting this. This change is not a mistake, but an accessibility fix for bug #485712. You still can customize the colors of the charts, so you can change it, only the default has been changed to be easier to distinguish for colorblind people. Because of this I am setting this bug to Invalid.
** Changed in: gnome-system-monitor (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/910223 Title: gnome-system-monitor color scheme changed between 3.2.1 and 3.3.3 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-system-monitor/+bug/910223/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs