Hairlines in background colour remain when highlighted area eased
Something I've been noticing recently is background-coloured vertical hairlines left behind when using a TrueType font, writing a text "button" using a coloured background when the screen is generally black and then writing plain text in the same location.
It's almost like the coloured background has been calculated 1 pixel wider than necessary to ensure adjacent cells touch, but the same rule doesn't apply for a black background.
There’s a 99% chance this is an issue in your graphics drivers.
We don’t deal with pixels – we tell GDI to draw text. GDI then tells your graphics driver to draw text, lines & curves. Pixel ghosts like these are usually driver issues.