Took a look at your image and after some thought came up with an idea that might help.
Perhaps increasing the size of the icon image a little bit is the answer.
After increasing my black cat icon image from 24px to 28px.
My black cat icon image is precisely 28 x 28px.
Code: Select all
#PanelUI-menu-button
{
list-style-image: none !important;
background: transparent url("blkcatsitting.png") no-repeat ! important;
background-size: 28px !important;
}
https://s8.postimg.org/5cgk8orud/UI-men ... mputrs.png
Note that the black cat icon is now 28px in size.
Used Gimp2 to scale the image size to 28 x 28px.
Hope this helps you and Happy userChrome.css tweaking!