Step 1:

Pick the photo that you want to modify, size or quality is not a problem here but a good photo is always nice.

Step 2:

Select your Brush Tool, and choose white as your Foreground color and Black as your Background color.

Step 3:

Press CTRL + SHIFT + N (create a new layer) and name it "Skin".we are going to use this one to paint the body.

Step 4:

Alright! Now the manual part, in your new layer fill the skin of your character like in the screenshot, be very very carefully and don't fill the clothes or the hair, just the skin.

Ok, now change your skin layer Blending Mode to Hue.

Now that you have changed the Blending Mode, your photo Character's skin is looking in a sort of Grayscale:

Step 5:

Ok, now choose the color that you like for the clothes we have chosen this awesome Dark blue (465972).

Create a new layer again (CTRL + SHIFT + N) this time name it "Color".

And Fill all the clothes like in the screenshot, again be very carefully with your Brush Tool.

Now change your "Color" layer Blending Mode, this time select Color.

Now your photo is looking awesome uh?

Step 6:

Select your background layer (the one with the original photo) and press CTRL + B (Color Balance).

Now tweak a little the settings to make the color of background match with the new colors of the hair and clothes.

And that's all! We're done here's our result, we wanted a Dark Looking photo, you can always play with the colors to get YOUR desired effect.