With the release of Chrome 69, I found the tabs to be a little too bright and similarly colored, so I decided (after minimal searching) to make a grey-ish theme, where I could more easily tell the active tab from other tabs.
New tab page has also had it's background turned grey.
I haven't really touched Incognito stuff. It's already nice and grey.
The buttons (Back, Forward, Reload, etc) have been made a little lighter, otherwise the 3-dot-menu in the top right kinda vanished. This means that the blue colors in the bookmark star on the left of the bookmark bar, and the blue of the extension icon on the extension page, they have also both been turned a pale grey color.