Highlight current page in sidebar widget

If your theme puts this item in a separate class — yes.

ps. That theme, which i’m using, puts class="current_page_item" for current item. Probably, not the theme does this, i’m using Flexi Pages widget… Sorry for the noise, if any.

In you stylesheet:

.current_page_item {
  background: yellow;
}

Or what’s the question?-)