When you want to dazzle them with color
Plant an annual out of the ordinary. Simply amazing to me that a plant from the deserts of South Africa's Namaqualand can be used for these sorts of color effects at any time of the year here in California. Our own native wildflowers are not nearly so accomodating for forcing into bloom in the dead of winter as this Linaria reticulata 'Velvet Red', which I am willing to bet, most gardeners in the rest of the country have never planted. Combined here with another South African succulent, Bulbine frutescens 'Hallmark'. So many other great and distinctive color forms of the Bulbine that haven't made it into American gardens, but don't get me started.
Warning, if shocking red is not your thing, do not, I repeat, do not, click on this link...
Here is a link that might be useful: Simply shocking reds