is there a photoshop plugins that can convert black and white pictures to colored pictures?

Answer 1

I method:

Step 1: Select the color you want to do to a specific part of image
Step 2: Select "Brush Tool" {Size: Choose according to your needs --- Mode: "Overlay" or "Color" --- Opacity: 100 --- Flow: 100}
Step 3: Go nuts! Just paint the area of the picture you want to color

II method:
Remember that in this method you'll have to work with objects that are in the front and then go to the objects in the background.

Step 1: Change the image to color mode by Image ---> Mode ---> RGB Color (!!!IMPORTANT!!! Always check this)
Step 2: Zoom to about 200%
Step 3: Select the magnetic lasso tool {Feather: 1px --- Anti-aliased: Yes --- Width: 10px --- Edge Contrast: 10% --- Frequency: 100}
Step 4: Now click on the edge of any object Coat, Boot, Hat, Door etc... (Not the wall or the floor)
Step 5: Just move your mouse cursor around the edges of the object until you have a complete selection. Like this
{Tip: If your magnetic lasso tool doesn't go where you want it to, you can just click the points manually. To remove the last point just press backspace. Refer to Photoshop manual for more assistance}
Step 6: Press Ctrl+J to do "Layer via Copy"
Step 7: Go to Image --> Adjustments --> Hue/Saturation {Colorize: Yes}
Step 8: Now adjust the Hue/Saturation and Lightness until your object looks realistic.
{Tip: The realism of the resulting image depends on the experimenting you have done. And the amount of efforts put to small objects. Always remember to experiment with the "Brightness/Contrast option to make your objects looks better}
Step 9: Set the blending mode of the layer to "Color". You can experiment with others too...
Step 10: Do the same for every other object. (Remember to click on the Background layer first)
{Tip: Using "Magnetic Lasso" tool won't always do the work ... It is difficult to select the images using this tool...
So after using this tool... select the "Rectangular Marquee" tool and select the "Add to selection button" (Hold your mouse over the buttons to make the text appear" and then draw at the edges}
Step 11: To color the background (Ground, Wall) you need not worry about the selection too much because you have already colored the objects and put them over the top of the background...
So Click on the Background layer and just select the wall including the objects and directly apply "Hue/Saturation" to it...
Step 12: Layer ---> Flatten Image
Step 13: Image ---> Adjustments ---> Auto Levels & Auto Contrast & Auto Color

This should make you able to color most of the B&W images to color.

Answer 2

What? You want a piece of software to take a B&W image and somehow *know* what colours are supposed to be in it? How exactly do you expect that to work? You're living in a sci-fi movie if you think that's at all possible dude.