Is it a feature in some advanced cameras or it is made using photo-editing software like Adobe-Photoshop ? This can be done in Adobe Photoshop. Or the free program called the Gimp.
You can add the colour yourself if you only have a black and white photo, by either painting the colour or making a selection and adding the colour in.
If you have a colour photo, an easy way to mix black and white with colour is to make a copy, choose to make that copy black and white, and then place it on top of the colour photo. Erase the black and white photo where you want the colour to show through. Ah, the power of photoshop.
Open your full color file in photoshop. (There are a number of ways of doing this, but I'm gonna share the easiest way of doing it while still being precise) First, duplicate the original layer. You should now have two layers of the same color image. Take your new top layer and desaturate all the color using the hue/saturation function located in the "Image" menu at the top of the screen. Your image should now appear b/w. Select the erase tool and erase the area that you would like to make color. You have to be careful about your brush selection when doing this. Start with a sizable, diffuse brush and work your way down to smaller more hard-edged erasers to get the cleanest effect.
Good luck | 