When used with timestamped console output, the formatting from one line sometimes (but not always) leaks over and colors the timestamp on the next line.
Timestamp background color white
Timestamp CSS style is problematic
IIUC it was more that switching to a console annotator was expected to make it easier to fix this, as outlined in the note of 2016-10-04.
We have an issue where [0m (aka setaf 0) is being printed to the screen at the end of a line with color and timestamps. This messes up the color for all future lines, though the timestamps themselves are okay.
Recheck after PR 137 (unreleased as of this writing).
And if PR 137 doesn't help, it would be worth checking if PR 147 makes a difference.
As a workaround, when the timestamper background is white, while the console was set to black in Ansi-Color plugin,
you can use https://github.com/jazzzz/jenkins-black-console to configure the default CSS to black.
All you need is to install Simple Theme Plugin and configure in "Manage Jenkins" this theme: