and after using Gpick to pickup the actual color used in Inkscape, I noticed that while Breeze theme demanded #31363b tooltip background color(which is pretty dark), the actual color used in Inkscape is #efece7, which is nearly the same with the tooltip foreground color, causes the issue.
I suspect that somewhere in Inkscape has overridden the tooltip background color with #efece7.
I investigated the Breeze theme and noticed that it has the following `gtkrc` settings:
gtk-color-scheme = "tooltip_ fg_color: #eff0f1" bg_color: #31363b"
gtk-color-scheme = "tooltip_
and after using Gpick to pickup the actual color used in Inkscape, I noticed that while Breeze theme demanded #31363b tooltip background color(which is pretty dark), the actual color used in Inkscape is #efece7, which is nearly the same with the tooltip foreground color, causes the issue.
I suspect that somewhere in Inkscape has overridden the tooltip background color with #efece7.