Liturgical Pimpernel, whose readership is far greater than my own, was kind enough to advertise this humble corner of the internet here: The Liturgical Pimpernel: Ask Father...and get a good answer!
Of course, as he mentions, I neglected to highlight the importance of the so rarely seen Rose-colored vestments that are worn only twice a year, once in Advent, and once in Lent. It's a pity that they are not seen more often, as a true "rose" vestment is beautiful (though, unfortunately, most turn out disastrously pink). As we approach Advent and Lent, I'll most likely echo the famous Fr. Z by posting about rose vestments in particular.
At the right is a photo of a true rose-colored vestment. (Photo comes from St. Bede's Studio, via The New Liturgical Movement)