You must have seen the cool effects in images where only a portion of the image is shown in grayscale and the rest is color. For example, an image where only lips of a woman are color and the rest is grayscale (black and white). Usually you need an advanced software like GIMP or Photoshop to achieve this, but if you want to quickly achieve this effect, then you can use the free Photo Black & Color software to do the same.
You can download Photo Black & Color from the website of PhotoFiltre software. The download is a portable application of very small size. You can extract the contents of the downloaded ZIP file and run PhotoBC.exe from there. The next thing you have to do is open an image file in this application. Photo Black & Color supports all sorts of image files including very popular formats as well as some less used image formats. Pictures with a smooth, uniform or gradient background give the best result, but you can open any sort of image.
Now you can select the colors from the image that you want to retain by clicking on the image points. This would add these colors in the left-side listbox. You can adjust the tolerance for increasing or decreasing the amount of grayscale in the resulting picture. Through experiment, I have found that a tolerance value of 35 works the best. Finally, you can click on the Execute button to process the image. It would take some time before showing you the results. You can save the results into an image file on your hard disk or print it directly to your connected printer.
So if you want to impress your friends by selectively removing color from their photographs, then you can use the free Photo Black & Color program. It is very easy to use and displays the results immediately that you can save to you hard disk and share with friends.
You can download Photo Black & Color from http://www.photofiltre-studio.com/freeware/photobc-en.htm.