You can modify the CSS behind that hover action to make the color a darker grey, or even change it altogether. After a quick look, I modified the hover to a darker grey using this, where #bbbbbc is the darker grey:
ul.treemenu a[href]:hover>span,ul.treemenu a[href]:focus>span,ul.treemenu a[href].hover>span{background-color:#bbbbbc}
Just realize this change *may* impact more than the tree menu hover...
Derek Curtis
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SmarterTools Inc.
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