wordpress-skeleton/blog/wp-content/plugins/after-the-deadline/tinymce/css/content.css

.hiddenSpellError
{
   border-bottom: 2px solid red;
   cursor: default;
}

.hiddenGrammarError
{
   border-bottom: 2px solid green;
   cursor: default;
}

.hiddenSuggestion
{
   border-bottom: 2px solid blue;
   cursor: default;
}