Adjust colours selectively with PhotoShop and Picasa..

wanna make pics like these???
You could selectively adjust colors to a photo in many ways by photoshop.
one way is to select the object you wanna colour using the selection tools like lasso tools, color range selection,etc best one though is to use the quick mask method. Now im not going to teach you how to use these tools, jst google themn they're quite simple. Now that you have selected the object, now invert the selection by invert selection option in selection menu(Select > Inverse). Next Add a new adjustment layer to the selected pixels by going to Layer > New Adjustment Layer > Hue/Saturation. Now if u wanna fade out the other area adjust saturation, if you want to change color adjust the hue levels,as simple as that
Another method in photoshop is to create an duplicate layer of the original but a faded one or colored one. and erase out the part you dont want to be coloured or faded.
This technique is also known as focal black and white in picasa. In picasa you could directly select the Focal B/W option in the effects and select the portion you wanna have color. Have Fun..