I could not demonstrate this in the violin, but it looks like it can work.
IcoMoon are styled in: in front of the pseudo-selector. Accordingly, the css pseudo-selector with the first letter should work on the generated content and, thus, include: before the data.
So including
.glyph2:first-letter {background-color: blue; color:white}
You should be able to give this view the first icon (generated in a: in front of the pseudo-element with 2 custom characters).
He worked for me locally, but I could not get him to work on the violin.
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